Question

identify the cross section of the triangular prism.
assume objects are perpendicular if they appear so.

Explanation:

A triangular prism cut by a plane that intersects all three rectangular faces (not parallel to the triangular bases) results in a quadrilateral cross-section, which matches the fourth option. The other options do not fit: a triangle would be a cut parallel to the bases, circles/annuli are impossible for a prism with triangular bases.

Answer:

D. The quadrilateral (rightmost orange shape)