Aplane intersects a prism to form a cross section that is a polygon with five sides. the minimum number of sides that the polygon at the base of the prism must have is? a.) 2 b.) 4 c.) 7 d.) 3 e.) 5

Since the plane if cutting through the prism to make 5 sides, than the original shape needs to have less than 5.
 A prism, is a 3D shape, so you can't have a 2 sided shape.

Now you have a choice of 3 or 4 sides.

A 3 sides shape is a triangle, which also can't be cut into a 5 sided prism,
 so the answer would need to be 4.
 The answer is B