The correct options are
A bond order
B π-bonding
C state of hybridization
Bond length depends on bond order and the presence or absenc of pi bonds.
A multiple bond has shorter bond length than single bond.
Thus, the options A and B are correct.
Bond length also depends on the state of hybridization or percentage s character.
Since ans s orbital is smaller than p orbital, the bond length decreases with increase in the s character. Hence, the option C is correct.