Robert F. Kennedy was assassinated in 1968. Which of these is true about his assassination?

A) He was assassinated in Dallas, Texas during a parade.
B) He was assassinated by Lee Harvey Oswald because of his stance on civil rights.
C) He was assassinated while working to end a worker's strike in Memphis, Tennessee.
D) He was assassinated while campaigning to be the Democratic candidate for the presidential election in 1968.