Answer:
D
Explanation:
Bob Marshall was an American wilderness and forest activist and the one of the brains behind the establishment of Wilderness Society in 1935. He was also known for the fighting of the rights of Native Americans.
He was plagued with different illnesses such as Ulcer and Hepatitis. However in November 11,1939 at the age of 38 he died. The official cause of death was discovered to be myelogenous leukemia and heart failure.