If the light of wavelength $\lambda$ is incident on metal surface, the ejected fastest electron has speed v. If the wavelength is changed to $\frac {3\lambda} {4}$ , the speed 4 of the fastest emitted electron will be :

Question

( A ) Zero
( B ) 2v
( C ) Greater than $\sqrt{\frac{4}{3}} v$
( D ) Smaller than $\sqrt{\frac{4}{3}} v$