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.
The overall theme about Government that is communicated by the preamble and the bill of rights is : Protect the rights of the people
Both of the preamble and the bill of rights protect the people from various abuse of powers whether it come from the majority or the Government itself
hope this helps