In 1976, Bill Clinton was elected state attorney general of Arkansas, a position he help for 2 years.
Then, in 1978, Bill Clinton became the governor of Arkansas, although he lost the re-election in 1980. He then later became governor again from 1982 to 1992.
Bill Clinton ran for president in 1992, and won the election that year. He was the 42nd US President, lasting from 1993 to 2001.
However, Bill Clinton was never a senator.
So the answer is C. senator.
Hope this helps!