Explanation
Correct option is A)
One of the earliest pesticides which were used by man was margosa (neem) leaves. The dried leaves repel the pests from stored grains. There is a compound called as azadirachtin present in the leaves of neem plant. This compound is also present in leaves along with other alkaloids. These compounds act as an insect repellant. Thus, they were used as insecticide and pesticide. Whereas pyrethrum, nicotine and dichorophenyltrichloroethane are the modern pesticides.
So, the correct answer is option A.