Answer:
Step-by-step explanation:
The only answer I can think as being possible is the last one. Pesticides are chemicals that go after unwanted animal life. They do not know that they should not attack human beings.
Infertility could very well be one of the side effects of a pesticide. There are others as well. Some pesticides go after the central nervous system (think mice and rats) and those are dangerous to use and to leave around.
The others all involve occupations that either require authentic abilities or mental astuteness. Neither should affect a man's ability to reproduce.