Answer:
Epinephrine, also known as Adrenaline
Explanation:
Adrenaline impacts short-term mood and can take seconds to flood your system.
*it may also be cortisol, I'm not sure if there's more context. Cortisol takes longer to work and can have long-term effects.
Answer: If enough evidence accumulates to support a hypothesis, it moves to the next step — known as a theory — in the scientific method and becomes accepted as a valid explanation of a phenomenon.