3. Single protons or electrons may be fixed in place at any locations A, B, C, or D, around a neutral conductor, as shown in the figure. Which combinations of XW charges at these labeled locations will result in an arrangement of surface charge on the block (not shown) that produces the desired electric field, Esurface, drawn at the center of the block? Esurface represents the electric field due to all charges on the block's surface. A x surface x C (1) electron at A, electron at B, proton at C, proton at D 2 electron at A, proton at B, electron at C, proton at D 3 proton at A, proton at B, electron at C, electron at D proton at A, electron at B, proton at C, electron at D no polarization will give this result for Esurface4. Three charges are placed at locations A=0, B=+x, and C=+2x along the 3: axis. Which, if any, of the following possible arrangements of charge will produce a net electric eld at location C pointing to the left? I. +Q at A, 2Q at B, Q at C. II. +4Q at A, Q at B, +Q at C. III. +Q at A, Q at B, +Q at C. (1) I and III (2) I only (3) III only (4) II and III (5) II only