We wish to see inside an atom. Assuming the atom to have a diameter of `100` pm, this means that one must be able to resolve a width of say `10` pm. If an electron microscope is used, the minimum electron energy required is about
A. `1.5 KeV`
B. `15 KeV`
C. `150 KeV`
D. `1.5 KeV`