According to Valence Bond Theory,which Atomic Orbitals of Carbon May

According to valence bond theory,which atomic orbitals of carbon may be hybridized to account for bonding? Why?

A) 1s, 2s, and 2p orbitals all may hybridize; these orbitals are of the same phase.
B) Only 2p orbitals may hybridize; the 2p orbital is carbon's highest-energy atomic orbital.
C) Only 1s and 2s orbitals of carbon may hybridize; each contains electrons to share in bonding.
D) Only 2s and 2p may hybridize; these orbitals contain valence electrons used in bonding.
E) Only 2s orbitals may hybridize; these orbitals contain valence electrons.