Which of the following statement is not correct for sigma and pi- bonds formed between two carbon atoms ?
A. Sigma -bond determines the direction between carbon atoms but a pi-bond has no primary in this regard
B. Sigma -bond is stronger than a pi- bond
C. Bond energies of sigma and pi-bond are of the order of `264 kj//"mol"` and `347 kJ//"mol"` ,respectively
D. Free rotation of atoms about a sigme`-`bond is allowed but not in case of a pi`-`bond.