The question asks to identify which of the listed plants is both a source of a drug and native to America.
Let's examine each plant:
Based on their native regions, Erthroxylum coca is the plant from the list that is native to America (South America) and is the source of a well-known drug (cocaine).
The plant Erythroxylum coca (option B) is native to South America and is the source of cocaine, a powerful drug used as a stimulant and anesthetic in medicine.
Other plants mentioned are:
Thus, the correct answer is (B) : Erthroxylum coca.