Which of the following statements would be accepted as a valid criticism of the big bang theory in scientific circles?
A. It cannot be tested directly.
B. It is just an educated guess.
C. It can be revised at a later date.
D. It does not explain how stars are clustered.

Aform of energy that is reflected or emitted from objects in the form of electrical and magnetic waves that can travel through space. there are many forms of  electromagnetic  energy including gamma rays, x rays, ultraviolet radiation, visible light, infrared radiation, microwaves and radio waves.