This sentence does not use a comma where one is necessary. Commas should always come before any direct quotation that appears in the middle of a sentence. A comma should appear after the word "said." Note that one of the choices offers this, but has single quotation marks (single quotation marks should only be used when the quote appears within another existing quotation). The correct choice is, "once said, "Life isn't about finding yourself. Life is about creating yourself." "

The words "sleek" and "fast" are coordinate adjectives: adjectives that modify the same noun separately, but are not separated with a conjunction. Coordinate adjectives need to be separated with a comma. The correct answer choice is, "The sleek, fast car broke."

The words "small" and "rare" are coordinate adjectives: adjectives that modify the same noun separately, but are not separated with a conjunction. Coordinate adjectives need to be separated with a comma. The correct answer choice is, "She sought the small, rare collectible."

This sentence does not contain commas where necessary. The phrase "which led to the building" is an example of a relative clause, which gives more information about its antecedent: the path. Any such phrase that occurs in the middle of a sentence must be introduced and completed with a comma. The correct answer choice is, "path, which led to the building, was."

This sentence does not contain a comma where necessary. The words "long" and "detailed" are coordinate adjectives: adjectives that modify the same noun separately, but are not separated with a conjunction. Coordinate adjectives need to be separated with a comma. The correct answer choice is, "The boy wrote a long, detailed letter."

This sentence contains a comma where one is not necessary. The word "that" as it is used here does not require a comma before it. The word "that," while is begins a new clause, is not separated from the main clause with a comma (e.g. same happens with the word "because"). The correct choice is, "Janice decided that she would visit."

This sentence contains a comma where one is unnecessary. Commas only appear before conjunctions when that conjunction joins two independent clauses; however, the phrase "small and noisy" is not an independent clause. Omit the comma. The correct choice is, "machine was small and noisy."

This sentence contains a simple error in its usage of a comma. This comma interrupts a clause, rather than punctuating one. "Good music is" is the beginning of a clause, it is neither a dependent nor an independent clause, and thus cannot have a comma at the end of it. The sentence is bet corrected by simply removing the comma.

This sentence does not contain a comma where necessary. The words "important" and "annual" are coordinate adjectives: adjectives that modify the same noun separately, but are not separated with a conjunction. Coordinate adjectives need to be separated with a comma. The correct answer choice is, "for the important, annual meeting."

This sentence does not contain a comma where necessary. The phrase "While flipping through books" is an example of an introductory phrase, explaining information necessary to the context of the sentence, but outside of the main sentence, grammatically. These types of phrases must be followed by a comma in order to separate them from the rest of the sentence. The correct answer choice is, "While flipping through books, Masha noticed."