One important result of the Crusades was that a Muslim communities in Europe grew larger.
b the Church began studying Islamic texts.
c there was an increase in trade and cultural exchange between Europe and the Middle East.
d a permanent crusader base was established in the Middle East.

I think its A

Explanation:

While the Crusades ultimately resulted in defeat for Europeans and a Muslim victory, many argue that they successfully extended the reach of Christianity and Western civilization. 

d. japan's attack on pearl harbor

affirmative action refers to the policies that take gender, race, or ethnicity into account in order to promote equal opportunity.

employers subject to title vii are prohibited from taking race or sex into account in any employment decisions. aa is a penalty for having any job group substantially statistically "underutilized" in any race or either sex. the employer must take steps to eliminate the underutilization, then stop, ending its aa efforts