Lunch counter sit-ins and the actions of freedom riders are examples of

a. violent acts by the black panthers

b. programs dealing with affirmative action

c. nonviolent attempts to oppose segregation

d. steps taken in support of the americans with disabilities act

The answer would be C.  Lunch counter, sit-ins, and the actions of freedom riders are clearly examples of ninviolent attempts to oppose segragation.
The lunch counter, sit-ins and the freedom riders are aiming to test the desegregation laws in different public places.  Blacks are trying do what the whites do, and visit what the whites visit, but they were usually denied access.

Use the formula: (n-2)×180, where n is the number of sides(18-2)×180= 28800, now this is the full exterior angle of 18-gon so you divide it by 18.28800÷18=160

Ais your answer