Which of the following options correctly describes the different behaviors in the reactions between a post and beam versus a rigid frame under a uniform load?

A) The reactions in a post and beam remain constant throughout the structure, while in a rigid frame, the reactions vary along the length of the frame.
B) The reactions in a post and beam vary along the length of the structure, while in a rigid frame, the reactions remain constant.
C) Both the post and beam, as well as the rigid frame, exhibit constant reactions throughout the structure.
D) Both the post and beam, as well as the rigid frame, exhibit varying reactions along the length of the structure.