Homolytic fission of C-C bond in ethane results in the formation of two free radicals. In order to understand why the carbon in the intermediate is sp2-hybridized, we need to consider the electronic configuration and bonding in ethane.

1. Electronic Configuration of Ethane:
Ethane (C2H6) consists of two carbon atoms and six hydrogen atoms. Each carbon atom has four valence electrons, while each hydrogen atom has one valence electron. The electronic configuration of carbon is 1s2 2s2 2p2.

2. Bonding in Ethane:
In ethane, the two carbon atoms are bonded together by a sigma (σ) bond formed by overlap of sp3 hybrid orbitals. Each carbon atom in ethane undergoes sp3 hybridization, where one s orbital and three p orbitals combine to form four sp3 hybrid orbitals. These hybrid orbitals are arranged in a tetrahedral geometry around each carbon atom, with the four sigma bonds formed by overlapping these hybrid orbitals with the s orbitals of hydrogen atoms.

3. Homolytic Fission of C-C Bond:
During homolytic fission of the C-C bond in ethane, the bond breaks symmetrically, and each carbon atom retains one of the shared electrons, resulting in the formation of two free radicals. In this process, each carbon atom gains an unpaired electron in its p orbital.

4. Hybridization of Carbon in the Intermediate:
After the homolytic fission, the carbon atom in the intermediate has three sigma bonds and one unpaired electron in its p orbital. This arrangement is characteristic of sp2 hybridization, where one s orbital and two p orbitals combine to form three sp2 hybrid orbitals. These sp2 hybrid orbitals are involved in forming the sigma bonds with the remaining hydrogen atoms and the other carbon atom.

Therefore, the correct answer is option 'B' - the carbon in the intermediate is sp2-hybridized.

In summary, during homolytic fission of the C-C bond in ethane, the carbon atoms in the intermediate are sp2-hybridized. This is because the carbon atom in the intermediate forms three sigma bonds and has one unpaired electron in its p orbital, which is consistent with sp2 hybridization.