Data from Epidemiologic Studies of Human Populations Exposed to Doses

Data from epidemiologic studies of human populations exposed to doses of ionizing radiation sufficient to cause this syndrome have been obtained from
1) atomic bomb survivors of Hiroshima and Nagasaki.
2) Marshall Islanders who were inadvertently subjected to high levels of fallout during an atomic bomb test in 1954.
3) nuclear radiation accident victims,such as those injured in the 1986 Chernobyl disaster.
4) patients who have undergone radiation therapy.

A) 1,2,and 3 only
B) 1,3,and 4 only
C) 2,3,and 4 only
D) 1,2,3,and 4