Answer :
a. Potent
When we use potent as an adjective, we are talking that which has a strong effect. For ex: a potent medicine, is one that has a strong effect on the disease it's meant to aid. That which is potent tends to have the qualities of forcefulness, vigor, and power.
When we use potent as an adjective, we are talking that which has a strong effect. For ex: a potent medicine, is one that has a strong effect on the disease it's meant to aid. That which is potent tends to have the qualities of forcefulness, vigor, and power.