Which statement is always true?

1. A cross section parallel to the base of a right rectangular prism is a square.

2. A cross section perpendicular to the base of a right rectangular prism is congruent to the base.

3. A cross section parallel to the base of a right rectangular prism is congruent to the base.

4. A cross section perpendicular to the base of a right rectangular prism has the same dimensions as the base.