The finding that light in free space has one speed, and one speed only, is consistent with ____________________. A) the conservation of energy as shown by Maxwell.B) general relativity.C) Newton's laws of motion.D) electromagnetic induction.

My book tells me it is A and D but it is only asking me for one answer??

2 answers

B) general relativity

Second postulate of special relativity:
The speed of light in free space has the same value C in all inertial frames of reference.
IT MARKED THIS ANSWER WRONG