The radiation dose that causes a large decrease in white-blood-cell count is:?

Question

A. 25–50 rem
B. 100–200 rem
C. 200–300 rem
D. 500–600 rem

Answer 1

Probably C. A 500-rem dose is typically fatal.

Answer 2

Unfortunately my text gives dose effects in grays, but this article from Wikipedia seems to have the information you are looking for.
"2–3 Sv (200–300 REM)
Severe radiation poisoning, 35% fatality after 30 days (LD 35/30). Nausea is common (100% at 3 Sv), with 50% risk of vomiting at 2.8 Sv. Symptoms onset at 1 to 6 hours after irradiation and last for 1 to 2 days. After that, there is a 7 to 14 day latent phase, after which the following symptoms appear: loss of hair all over the body (50% probability at 3 Sv), fatigue and general illness. There is a massive loss of leukocytes (white blood cells), greatly increasing the risk of infection. Permanent female sterility is possible. Convalescence takes one to several months."

Hope this is helpful.

Answer 3

B