Answer:
A. 1.65 x 10^-10 m
Explanations:
The relationship between the speed(v), frequency(f), and wavelength(λ) of an electromagnetic wave is given as:
v = λf
From the question:

Substituting the values of v and f into the equation v = λf

Therefore, the wavelength of the electromagnetic wave is 1.65 x 10^-10 m