[单选题]
What happens to the kin fmu )leu+jn,g.r;-k netic energy ofxese912 we;5qvyj w(f a speedy proton when its relativistic mass doub1 ;es2fqe95( evyjxwwles?
A. It doubles.
B. It more than doubles.
C. It less than doubles.
D. It must increase, but it is impossible to say by how much.