See the multi-choice question below:

Sentence 1: Realizing how easily this man's smile had disarmed him, Adrin grew even more nervous.

Sentence 2: Adrin knew the man was up to something by his smile.

If the first sentence is true, then is the second sentence true?
Pick from:
[a]. yes
[b]. it is not possible to tell
[c]. no
[b].