Why Did Britain Seek to Control the Ohio Valley

Why did Britain seek to control the Ohio Valley?

A) To continue its expansion west and block French land-grabbing and influence
B) To ensure defeat of the French in the War of Jenkins´s Ear
C) To halt the growth of Spanish colonization in North America
D) To secure the Mississippi River and continue pushing further south to control all of Mexico
E) To link their Canadian holdings with those of the lower Mississippi Valley