Answer:
C. Even though he is being rejected by those at the table, the speaker is confident and resilient to adversity.
Explanation:
The above statement is the one that actually captured what he means by the statement "growing strong". To him, he noticed that, he is being treated different from others because he happens to be black but that does not deter him from be confident about himself rather than complaining always. He showed resilient to the adversity he is currently facing by making such that he feeds well when sent over to the kitchen.