What challenges did katherine johnson face while working at NASA

The main challenges faced by Katherine Johnson were segregation and discrimination. As an African-American, she was faced with segregation as a child, due to her ethnicity. When she worked at NACA, she not only was discriminated because of her race, but also her gender.

the difference is that white collar worker performs skills like worker as a scientist or well blue collars do physical work and they do services like being a cook.

i believe the correct answer is b.