GMAT Reading Comprehension (RC) | Items that seem unremarkable today might once have altered the course

Asdfg, to me Ans A is badly worded. "Logic"? "Claims"? There's only one claim.

If you rephrase it to something like -
" . . . uses an example to finish a train of thought."

" . . . completes/supports a statement with an example."

- then it's clearer, though probably too easy, to the writer/writers.
Ans D is tempting, but for "importance;" "randomness" would be, as they say,
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