Brevity

Usually, on the SAT, the shortest grammatical sentence is the right answer

CLUTTERED: The chapter at the end of the book was very profound.

REVISED: The last chapter of the book was profound.

CLUTTERED: The theme of the book is that people should not judge other people until they've had a chance to walk in their shoes.

REVISED: A recurring theme of the book reminds us that we can't judge others until we've walked in their shoes.

Cluttered: The man who was in the new car waved at us.

Revised: The man waved at us from his new car.

Cluttered: The paragraph at the end of the essay needs to be revised.

Revised: The last paragraph needs to be revised.