Respuesta :
A. 1967/1968
The other answers weren't even during the time of the Vietnam Conflict, whereas Option A even coincides with protests close to Kent State in 1970.
The other answers weren't even during the time of the Vietnam Conflict, whereas Option A even coincides with protests close to Kent State in 1970.
Your answer is A. B is too far back, C is more around the Korean war, D is close, but not the answer.