electromagnetic waves

[dreamer8987]

the amplitude of the electric field component of and electromagnetic wave is increased from E to 4E. What is the corresponding change in the intensity of the wave?
a) the intensity is unchanged by the increase in E
b)the intensity increases by a factor of 16
c) the intensity increases by a factor of 4
d)the intensity decreases by a factor of 4
e)the intensity decreases by a factor of 16