Answer
choice $C$ $(6.45\times 10^{14}Hz)$
Work Step by Step
Velocity, frequency, and wavelength are related using the formula $$v=f\lambda$$ Solving for frequency yields $$f=\frac{v}{\lambda}$$ Substituting known values of $v=c=3.00\times 10^8m/s$ and $\lambda=465nm=465\times 10^{-9}m$ yields a frequency of $$f=\frac{3.00\times 10^8m/s}{465\times 10^{-9}m}=6.45\times 10^{14}Hz$$ This corresponds to choice $C$.