Answer:
C) Anybody rather not chance a search?
Explanation:
From the excerpt, the sentence that adds the most suspense was "Anybody rather not chance a search?".
It's clear that from the excerpt, Ellery is a law enforcement officer or someone that is keen to catch a thief or make a discovery of sorts so the following monologue takes place, "Sorry I can't produce the thief with a flick of my wrist, the way it's done in books, but in real life, detection — like crime — is pretty unexciting stuff. We'll begin with a body search. It's voluntary, by the way. Anybody rather not chance a search? Raise your hand".
From the monologue above, Ellery is trying to solve a crime and he decided to do a body search of the most immediate suspects and the sentence that adds the most suspense was asking if anyone would object to a search. At this point, it is clear that anyone that objects to a search is the prime suspect because you won't object to a search if you don't have something to hide. It is also worthy of note that after asking if anybody objected to a body search, nobody responded.
This can be inferred to mean that everyone was scared not to be the first to object to a body search so as not to be seen as the prime suspect.
