What was the reason why the leaders in mecca initially reject muhammad's teachings?

a. islam represented a danger to mecca's economy because muhammad taught followers of islam to avoid trade with non-muslims.
b. the people of medina were afraid that the influence of islam would shift trade away from mecca to yathrib.
c. the spread of monotheism threatened mecca's economy, which relied on the wealth of non-muslim pilgrims.
d. muhammad's use of torture against nonbelievers of islam made those in mecca fearful of his new religion.