Lennie accidentally killed his pet. These foreshadowing moments establish Lennie's innocence and make his tragedy seem inevitable. Lennie's passion for stroking soft objects and his tendency to kill them are established when he kills Curley's wife. The reader doesn't think Lennie could premeditatedly kill.
Explanation:
This is just my own opinion. Of course, you are free to alter it to your own.
Elimination is always the best. Pick out the worst possible answers, so it'll give you less choices to pick from. Or you could always pick c. I wouldn't advise that. Good luck on your test. :)