$u=600 msec^{-1}$
$\therefore \Delta u=\large\frac{600\times 0.005}{100}$
$\Rightarrow 0.30msec^{-1}$
Now,$\Delta x.m.\Delta u=\large\frac{h}{4\pi}$
$\Delta x=\large\frac{6.6\times 10^{\large-34}}{4\times 3.14\times 9.1\times 10^{\large-31}\times 0.30}$
$\Rightarrow 1.92\times 10^{-3}m$
Hence (c) is the correct answer.