Which of the following describes a rectangle?

A rectangle is specifically defined as a type of parallelogram that possesses four right angles. This characteristic is fundamental to the definition of a rectangle, distinguishing it from other parallelograms, such as rhombuses which have all sides congruent but no requirement for right angles.

In a rectangle, the opposite sides are parallel and equal in length, and the angles formed at each corner are all exactly 90 degrees. This property ensures that it maintains the structure of a parallelogram while conforming to the stricter definition of having right angles—an essential aspect of rectangles.

Other descriptions, such as those involving irregular quadrilaterals or shapes lacking right angles, do not align with the characteristics of a rectangle. The correct recognition of the unique properties of a rectangle is crucial for understanding its role within the broader category of quadrilaterals and parallelograms.