Correct Option: B

Reveals: It is an external jamb of a window opening at right angles to the wall face. Reveals are the timber liners on the inside of the window. The part of the jamb opening which is exposed between the window frame and the face or back wall is known as Reveal.
Mullion: This is a vertical member, which is employed to subdivide a window vertically. Its main purpose is to provide structural support to an arch or lintel above the window opening or it runs through the shutter. Mullion is used as vertical supports, but some horizontal framing member may also be considered as a mullion.
Transom: This is a horizontal member of a window frame, which is employed to sub-divide a window opening horizontally. The shape of the transom window can be rectangular, arch or semi-cir cular. It can be made up of a perforated metal sheet or wooden sheet.