Why did the olmec civilization not depend on rivers for growing crops?

Don’t mind the already marked answer but taking it now

What happened as the result of a conflict between british troops and a colonial militia in massachusetts

By choosing to resupply fort sumter, abraham lincoln risked a. abandonment of the fort by union soldiers. b. abandonment of the fort by confederate soldiers. c. the appearance of giving in to confederate secession. d. armed conflict with southern soldiers.