What Was the Role of the Samurai in 17th and 18th

What was the role of the samurai in 17th and 18th century Japan?

A) They engaged in constant warfare which led to a decreased number of samurai.
B) They became an imitation of the Chinese system of mandarin officials.
C) They became superfluous and no longer served a purpose.
D) They overthrew the shogun and reinstalled the emperor.
E) They became foreign mercenaries to Western powers.