Which sentence is most clearly a topic sentence in a body paragraph from an essay?

A. One way Austen's first novel differs from her second novel is its
focus on a single character,

B. As these details show, Elizabeth Bennet is the main focus of
Austen's Pride and Prejudice.

c. In all three of the ways just described, the first two novels by
Austen differ considerably

OD. Pride and Prejudice and Sense and Sensibility are different in three
important ways

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