Answer:
(C) offering a specific example to support a general claim
Step-by-step explanation:
If there is only one claim: "Things which today seem unremarkable could have altered the course of history once...."
Even the answer choice's clarification mentions "the claim":
The second paragraph provides detailed details–perhaps even the position nutmeg played in New York history–to support the argument that apparently inconspicuous things can change the course of events.
So, shouldn't alternative "author say" consider instead of "author claims"?!