The principal involved in crop production include the following,
I. controlling of diseases, weed, and pests,
II. maintaining the quality of agricultural produce,
III. conserving and preserving of natural resources,
IV. controlling soil erosion.
Which of the following combination does the government aim at when making agricultural policies?
A. I and II only
B. III and IV only
C. I, II and III only
D. I, II,III and IV
E. II,III and IV
Correct Answer: Option D