It would be that "d. Muhammad was engaged in long-distance trade where he came into contact with monotheists" that likely would have influenced his acceptance of monotheism, since this allowed for him to gain new and challenging points of view.
B. Horses. I doubt they'd kill their own mounts unless they had to.
The answer to the question is B. Jainism. It was founded by Mahavira in the sixth century and the goal of the religion is to achieve liberation of the soul. It is a prehistoric religion that originated in India and teaches the way to liberation and happiness is to live a life without harm and renunciation.
