Answer:
Option C.
Explanation:
Solid in the given picture is a rectangular prism and a rectangular prism has 6 faces. Each face is formed by joining 4 vertices of the prism.
All the faces joining four vertices are: AFGB, BGHC, ADEF, DCHE, FEHG, ADCB.
From the given options,
Option (C). ADEF will be one of the face of the solid.