Answer:
Which of the following, if discovered to be true, would most seriously weaken the support for the researchers’ prediction?
The correct answear is B. Naltrexone inhibits morphine from triggering the migration of intestinal bacteria into the bloodstream.
Explanation:
Naltrexone is a non-selective opioid antagonist, it competes with these at the level of the receptors and thus reduces their effects.
The responses A, C, D and E does not weaken the support for the
researches ´ predictions, and are not relevant to the argument.