Final answer:
The most impactful passage from 'Notes of a Native Son' is the one emphasizing the emotional burden of the past, which aligns with James Baldwin's life struggles and themes in his work.
Step-by-step explanation:
In Notes of a Native Son, the passage that stands out as impactful in developing Baldwin's primary contrast is option b) "As he stood in the crowded room, the weight of his past pressed upon him like an unbearable burden." This passage effectively reflects the intense personal struggle and emotional burden James Baldwin depicts in his writings. Baldwin's experiences with his abusive stepfather, poverty, and his identities as a black, gay man in America shaped his writing and activism, which often confronted the complexities of identity and social injustice.