Line MN is the line of intersection of planes K and L.
Any ray from point B will have a name that begins with B. Available choices are BE, BF, BG, but ray BG does not have an opposite ray shown in the drawing. Thus your answer needs to be BE and BF.
Planes are named generally with a single letter (K) or by naming three points in the plane. Points ABGHMN are all in plane K, so naming any three (except ABG or MNG, which are all on the same line) will define the plane. The available choices in your list are G, B, N.
