The correct answer is a. Xerxes.
There were two Persian kings with the name Xerxes - Xerxes the First and his grandson Xerxes the Second. The name means "Ruling over Heroes"
The grandfather, Xerxes the First was the son of famous king Darius I. He ruled from 486-456 B.C. and he is known as one of the King of Kings of the Archaemenid Empire, famous for the invasion of Greece in 480 B.C.
The grandson, Xerxes the Second, ruled for forty five days until he was assassinated by his brother Sogdianus in 424 B.C., who was assassinated by Darius II, his illegitimate brother.
