The biggest role would be the Brain.
D. Regular Exercise has been shown to reduce the physical effects of stress.
A wouldn't be correct because at home, you can find plenty of time to relax.
B would be wrong because it is opinion based and would be extremely difficult, if not impossible to experiment for.
And C would be wrong because mental discipline doesn't necessarily means you can take away stress.
Hope this helps!
~GeeksandNerds
Answer:
Certo Pectin can help a person beat a marijuana drug test.
