Answer:
Synergistic.
Step-by-step explanation:
The stimulant might taken to improve the functioning or increasing the effect of any condition. Different drugs are present in market that might work as an stimulant.
The drugs that works as an stimulant increases the effect in presence of some chemicals compounds. The compound that increases this effect is known as synergistic and the effect is known as the synergistic effect. This effect may also mimics naturally as the drug.
Thus, the correct answer is option (C).