Based on molecular orbital theory, the bond order of the n-n bond in the c2 molecule is

The question is quite confusing because you are asking about the bond order of the N- N bond in the C2 molecule, you see that there is no N-N bond because it is only composed of C and C atoms. The bond order is based on the number of bonds on the atoms, so if there is double bond, so the order is 2. When it is triple bond the order is 3. For N-N alone for N2 molecule, the order is 3.