The correct option is C All are prone to over exploitation
Nepenthes:
Nepenthes (pitcher plant) is an insectivorous plant that has several medicinal properties. It is widely used in the treatment of leprosy, dysentery, cholera, gastrointestinal discomfort, night blindness, etc.
Psilotum:
Psilotum (whisk fern) is a plant species that is over-exploited for its use in wound healing. The spores of this fern are used as talcum powder under the loincloth to prevent chafing. The spores are also commonly used as a purge (removing impure things) in medicine.
Rauwolfia:
Rauwolfia (devil peppers) is overexploited for its medicinal benefits in the treatment of high blood pressure or hypertension.
Aconitum:
Aconitum (devil’s helmet) is used in the treatment of fever associated with cold, pneumonia, pain, inflammation, high blood pressure, laryngitis, asthma, and as a diuretic. This medicinal plant is widely used for its medicinal benefits.
Final answer:
c. All are prone to overexploitation