Kinetic energy =$\large\frac{1}{2}$$mu^2=4.55\times 10^{-25}J$
$u^2=\large\frac{4.55\times 10^{-25}\times 2}{9.108\times 10^{-31}}$
$u=10^3m/s$
$\therefore \lambda=\large\frac{h}{mu}$
$\Rightarrow \large\frac{6.625\times 10^{-34}}{9.108\times 10^{-31}}$
$\Rightarrow 7.27\times 10^{-7}m$
Hence (c) is the correct answer.