Answer:
The answer is c. dopamine.
Step-by-step explanation:
Dopamine is both a neurotransmitter and a hormone. Among other things, it is reponsible for reward-behaviour association.
Although it is considered as a "pleasant" chemical by popular culture, some studies have shown that it influences our motivation to perform certain tasks, based on the possible outcomes. In other words, it helps us make decisions depending on their perceived positive or negative consequences.