Idioms and Phrases - Verbal and Reasoning

In the following questions four alternatives are given for the idiom/phraseitalicised and underlinedin the sentence. Choose the alternative which best expresses the meaning of idiom/phrase.
Q1:

His plan was so complicated that it floored his listeners.

A entertained

B puzzled

C annoyed

D encouraged

ANS:B - puzzled

No answer description is available.