In electromagnetic waves, frequency is inversely proportional to
A: Amplitude
B: Wave Speed
C: Wavelength
D: Reflection

Frequency is inversely proportional to wavelength.Wavelength is the spacial period, and more generally the frequency is inversely proportional to the period.If the wave's speed if c, then f=c/l where l is the wavelength.

In electromagnetic waves, frequency is inversely proportional to C. Wavelength.