In the question below, a word is given in bold, and corresponding to it three sentences are given. Choose the option depicting the sentence(s) that have/ has the correct usage of the word.

Astound
(A)The latest cut-off of the banking examination will astound you.
(B) The child was astound to solve the math problem without any assistance.
(C) Please have your lunch as you must be astound after so long hours of working.