Question

the bases for a cylinder must be two discs that are parallel and: a. squares. b. have one lying directly above the other. c. similar. d. congruent.

Explanation:

A cylinder's bases are defined as two parallel discs that are identical in size and shape. Option A is incorrect because squares are not discs. Option B describes a right cylinder specifically, not all cylinders. Option C (similar) means same shape but different sizes, which does not fit, as cylinder bases must be identical. Congruent means identical in shape and size, which is the required property.

Answer:

D. congruent.