That would be spermicide.
The correct answer is A.
Q: But how, also, why?
A:

Formula to the solution should explain everything. ^
Decreased performance
Increased perceived effort during workouts
Excessive fatigue
Agitation and moodiness
Insomnia or restless sleep
Loss of appetite
Chronic or nagging injuries
Metabolic imbalances
~Ma-tiah
Tend to stay motivated (also nice venti pfp)
the question was uncertain, but from my years of being in school, i have learned that yogurt is probably the best answer