According to thehindu.com, it was defined that "true heroism" is:
A trusted friend and mentor described the concept of heroism<span>, not as an instinctive demonstration of bravery, but as an unselfish act performed even when aware of danger to self, through surmounting the fear by acting with courage.
</span>I hope my answer has come to your help. God bless and have a nice day ahead!
I would definitely say B.) A smile because if you were just staring it may be rude or distracting to the speaker and a smile shows you are listening and absorbing the knowledge
