How Has the Exposure to Shocks Been Shown to Affect

How has the exposure to shocks been shown to affect the likelihood of dying of cancer in rats?

A) Rats who had cancer cells implanted were more likely to die of cancer if they were exposed to shocks that they could not escape.
B) Rats who had cancer cells implanted were more likely to die of cancer if they were exposed to shocks that they could escape.
C) Rats who had cancer cells implanted were more likely to die of cancer if they were exposed to any type of shocks.
D) Rats who had cancer cells implanted were unlikely to die of cancer if they were exposed to any type of shocks.