Hi Candidate,

Hybridization in Central carbon atom refers to the number of Sigma- bonded groups attached to the main center. The hybridization in the carbon group is- ((CH3)3).C where the outer "C", is the central carbon atom. The central carbon atom is tied to three CH3 and one Hydrogen atom, which makes it sp3 Hybridization.

Hope that this answer helps you. Have a Good Day!!