Choose the incorrect option for bond strength.

The correct option is B $2p_{\pi }-3p_{\pi }>2p_{\pi }-3d_{\pi }$
B)
In $2p_{\pi }-3p_{\pi }$ less effective overlapping with respect to $2p_{\pi }-3d_{\pi }$

Difference in principal quantum, less efficient the overlap. Hence A and C are correct.
D)
Greater the principal quantum number, less efficient the overlapping and hence lesser the bond energy.