An electron of mass m has an uncertainty in its position r. What is the uncertainty in the speed of this electron?

A. \(\frac{h}{{4\pi r}}\)

B. \(\frac{hr}{{4\pi m}}\)

C. \(\frac{hm}{{4\pi r}}\)

D. \(\frac{h}{{4\pi mr}}\)

D