Think of each segment in the diagram as part of a line. which line or plane appears to fit in the description? (this is a rectangular prism - all angles in the corner are right angles.

Part A

This line contains point G (as an endpoint) and it runs perpendicular to line FE. This line is in the bottom face of the rectangular prism. This line is also in the front face as well.

Part B

AB is parallel to CD, GH and FE.

Part C

Skew lines are lines that aren't parallel nor perpendicular nor intersecting. Skew lines can only be found in 3D space (not 2D space). Think of a line on the ground running from north to south. If we had a straight wire that did not bend at all run from north to south, then we would have two parallel lines. However, if we aim the wire to go from east to west, then the line on the ground and the wire will be skew lines. The line on the ground and the wire line do not intersect. The same story happens with AB and FE, along with AB and AG.

Part D

The front face is plane AGF. We simply locate the three points A, G, F and note this is the front face. The back face is parallel to the front face. This face is plane GCH, and it contains point C.

note: we could say "plane AGFD" but we only need 3 points at minimum to uniquely determine a plane.