The original sentence contains an error in noun-pronoun agreement: the plural possessive pronoun "their" is used to refer to "the worker," a singular noun. We need to use a singular possessive pronoun to refer to a singular noun, and our choices in this case are "his," "her," and "its." One doesn't use "its" to refer to people, and while "the worker" is not a gendered noun, we can tell that the worker being described in the sentence is male because of the use of the possessive pronoun "his" in the phrases "his lost green helmet" and "made his way home happily." For the sentence to be correct, we need to replace "their" with "his," so the correct answer is "Just as he finished work for the day, the worker found his lost green helmet and made his way home happily."

Choose a pronoun that properly agrees with the subject. In this case, "basketball team" is singular, although it represents a group of people, and should be accompanied with "its," instead of "their."

Whenever a sentence refers to a person of unknown gender and a singular possessive pronoun is required that refers to that person, one typically includes both the masculine and the feminine possessive pronouns in the phrase "his or her." In this case, "his or her" is a better choice than "their" because "student" is a singular noun, and "their," which is a plural pronoun, does not agree with it in number. Considering the other potential answer choices, "they're" is the contraction of "they are," which would not make sense in the sentence, "it's" is the contraction of "it is," which wouldn't make sense in the sentence either, and "its" is the possessive form of the pronoun "it," which is not used to refer to a person. So, none of those answer choices can be correct.

The original text contains a pronoun agreement error. The intended antecedent of the pronoun "it" is supposed to be "books," which is plural and would therefore require the plural pronoun "them" instead of the singular pronoun "it."

The only answer choices that contain "them" instead of "it" are "that cause them to decay" and "that causes them to decay." The answer choice with "causes," however, uses this singular verb with a plural subject, "materials," and is therefore incorrect.

The original text "the person who has most significantly transformed the world through their charitable actions or scientific discoveries" and the answer choice "the person who most significantly transformed the world through their charitable actions or scientific discoveries" contain pronoun agreement errors because they incorrectly use the plural pronoun "their" to refer to the singular noun "person."

The answer choices "the person that has most significantly transformed the world through his or her charitable actions or scientific discoveries" and "the person that significantly transformed the world through his or her charitable actions or scientific discoveries" are incorrect because they use "that" to refer to a person, when "who" or "whom" should be used when referring to a person. (Remember to use "that" only when referring to non-human living things or objects.)

The answer choice "the person who has most significantly transformed the world through his or her charitable actions or scientific discoveries" is correct because it is the only answer choice that correctly uses "who" and the singular pronoun "his or her" to match the singular noun "person."

The pronoun refers to employees, so the pronoun should be plural rather than the singular he or she.

The use of "your" at the end of the sentence is confusing, as the only reference in the sentence is "a person," and the second person pronoun has no place in the sentence. Changing "your" to a third person possessive pronoun will straighten out this problem. Because we do not know whether the "person" in question is male or female, we should use the phrase "his or her." The correct answer choice, therefore, is "for the rest of his or her life."

The phrase as written in the underlined portion makes an odd reference. The subject of the sentence are the "rites," and not the religion. The faith needs to be specifically referenced, as well as being fully grammatically correct; therefore, "after the faith was no longer active" is the correct answer choice.

The plural possessive pronoun "their" does not agree with its singular subject, "the army." Even though "the army" represents a group of people, it is a singular noun, and should consequently be modified by the pronoun "its."

The final phrase of the sentence contains a problem with the pronoun "their" and its antecedent, "group." Because "every group" is a singular noun, it later needs to be referenced with a singular pronoun and verb, although the sentence already uses the appropriate verb form. The only answer choice which has appropriate agreement between all of the words is "every group of representatives was in its correct place on the stage."