im very confused pls explain each part

2) Answer the questions below (34pt) : a) Which two structures are correct and related by resonance as shown by the arrows drawn? A. 1 and 3 B. 1 and 4 C. 2 and 3 (D.) 2 and 4 Me b) Choose the structure of the trans isomer of C4H6Cl2 that depicts the net dipole moment, if any: A.) B. C. D. none c) Choose the structure that correctly depicts all the partial charges in this molecule