The correct answer is D) Business owners felt that favorable diplomatic policies with other nations would expand markets and access to raw materials.
The factor that caused business owners to support U.S. imperialism was " Business owners felt that favorable diplomatic policies with other nations would expand markets and access to raw materials."
Business owners decided to support US imperialism because they knew it was going to favor them. If the US gained territories, business owners could get access to raw materials and natural resources to manufacture goods ant their fabrics and industries. And then, later sell those products to those new lands.