Answer:
c. was assassinated by an unsuccessful office seeker
Explanation:
James A. Garfield was the 20th president of USA and he was the first sitting member of congress to be elected as the president of the nation. His service was short lived only for six and a half months until his death by assassination.
He was shot dead by Charles J. Guiteau at the Baltimore and Potomac Railroad Station in Washington, D.C. and died in Elberon, New Jersey. Guiteau's motive was avenge against Garfield for an imagined political debt.
Hence the correct option is c. was assassinated by an unsuccessful office seeker.