Which of the following statement is wrong?

• A

  A $\mathrm{σ}$-bond is shorter than a $\mathrm{π}$-bond. 

• B

   Bond energies of $\mathrm{σ}$ and $\mathrm{π}$ bonds are of the order of 264 and 347 kJ mol^-1

• C

  Free rotation of atoms about a $\mathrm{σ}$-bond is allowed but not in case of a $\mathrm{π}$-bond.

• D

  A $\mathrm{σ}$-bond determines the direction between C-atoms but a $\mathrm{π}$-bond has no primary effect which leads to bonding