What is the balanced oxidation half-reaction from the redox reaction below?

fe + cuso4 --> cu + fe(so4)3

2 fe yields 2 fe2+ + 4e-
2 fe2+ + 6e- yields fe
fe yields 2fe3+ + 6e-
2 fe yields 2fe3+ + 6e-

i need i think its either a or d

13. a covalent bond between two atoms is likely to be polar if: a. one of the atoms is much more electronegative than the other. b. the two atoms are equally electronegative. c. the two atoms are of the same element. d. the bond is part of a tetrahedrally shaped molecule. e. one atom is an anion.