A ruthless person will stop at nothing to get what he wants. "Merciless," meaning without mercy, is the closest to this meaning. For example:  "Tim was ruthless when playing hockey and knocked over anyone in his way." "Compassionate" is an antonym to ruthless.

"Cruel" and "brutal" both refer to intentional actions that cause harm to people. The other words might seem similar, but they are not as closely related as "brutal" and "cruel."

"Polite" and "well-mannered" are closest in meaning. The other words are not at all synonymous with "polite."

"Ignorant" and "foolish" are synonymous words. They refer to someone who doesn't know things or acts in a way that seems unintelligent or uninformed. "Ignitable" means that something is flammable. Although this word looks similar to "ignorant," they are not synonyms. The other answer choices also do not have meanings similar to "ignorant."

"Hateful" and "loving" are antonyms: they mean the opposite from each other. "Furious" and "enraged" are synonymous; they refer to someone who is extremely angry. "Grumpy" and "grouchy" are synonymous. They refer to someone who is in a bad mood and who might be acting a little mean. The word "grumpy" does not mean the same thing as the words "furious" and "enraged."

"Amiable" most nearly means to be agreeable or friendly. "Ornery" refers to a person who has a mean personality or demeanor, while "dismal" refers to something depressing or dreary. Both of these words have a negative connotation and are therefore not synonyms for "amiable." "Gratuitous" most nearly means excessive or unneeded and has no relation to "amiable." "Content" means a peaceful state, and has a positive connotation easily confused with "amiable." The best choice, however, is "agreeable" which is an exact synonym for "amiable." 

"Considerate" involves exercising deep thought to avoid negatively impacting other people. "Kind," which means to have a considerate and thoughtful nature, is the best synonym of "considerate."

Incorrect Answers:

"Upset" means very unhappy.

"Worrisome" means causing anxiety or concern.

"Antisocial" describes someone who does not enjoy the company of others. Generally, considerate people are not antisocial because they like to be around other people.

"Happy" involves showing pleasure for something.

"Ambitious" means showing a strong desire to succeed. "Driven," which means motivated, is the best synonym of "ambitious."

Incorrect Answers:

"Lazy" means unwilling to work or use energy. "Lazy" is an antonym of "ambitious."

"Slovenly" means messy and dirty.

"Rich" means having a lot of money.

"Decadent" means self-indulgent.

"Clever" means quick to understand and learn new ideas. "Intelligent," which means intuitive and quick-witted, is the best synonym of "clever."

Incorrect Answers:

"Incapable" means unable to do something.

"Classical" refers to a traditional or long-standing style.

"Wily" means deceitful.

"Sly" involves having cunning and deceitful nature, and is a synonym of "wily."

Cheerful and happy both relate to ones mood being in high spirits.