To accurately support the answer to PART A, it is important to identify the main theme or argument of the poem. Assuming that your answer to PART A involves themes of identity, alienation, or the feeling of being bound or constrained, I would suggest that option B. "Nothing we are, chained by parentheses." (Line 16) best supports that theme. This line directly suggests a sense of confinement or limitation placed upon identity, which ties into concepts of how people may feel trapped by societal labels or categories, often represented visually as parentheses.
If your answer to PART A focused on a different theme, please clarify, and I would gladly adjust the recommendation!