Which of the following statements is $NOT$ correct?

• A
  Hybridization is the mixing of atomic orbitals and also their combination into molecular orbitals.
• B
  $sp^2$ hybridization involves the mixing of two $p$-atomic orbitals and one $s$-atomic orbital.
• C
  In $dsp^2$ hybridization,all hybrid orbitals are at $90^o$ to each other.
• D
  In $d^2sp^3$ hybridization,the hybrid orbitals are directed towards the corners of a regular octahedron.