A point charge Q is held fixed at the origin while an external force is used to move a s...

A point charge Q is held fixed at the origin while an external force is used to move a second charge q from point A to point B along the three different paths shown in Figure 18.6. The charge q begins from rest and has zero velocity when it reaches B. Is the work done by the external force largest along (a) Path I, (b) Path II, or (c) Path III, or (d) is the work done by the same for all three paths?