deficient radiant Reviving stumped surpass stranddisperse deduce appeasedelapseA considerable period of time has to _________ before such security measures as closed-circuit television cameras become evident in reducing crimes.

Please choose a proper word to complete the sentence.The senators didn't expect us to ask such tough questions, and when we finally did, they got ( ) and didn't know what to say. A: shrewd B: discern C: stumped D: crumbled