If...
- (1) Harmful
(2) Available to the public
(3) Tax would discourage continued use
Then...
- Governments should tax it
I am predicting that the correct answer will satisfy all three requirements stated above and will conclude that this substance should be taxed.
(A) Says nothing about how the tax would discourage use. Eliminate.
(B) Harmful? Check. Available? Check. However, "the demand for these products will not be affected" is quite the opposite of "discouraging continued use." Eliminate.
(C) Harmful? Check. Available? Seemingly check. Discourage use? Check: "raised to give people an incentive to purchase OTHER pesticides." This is the correct answer.
(D) and (E) fail to discuss raising taxes. Thus, they cannot be correct.