Please someone answer this question and put my mind at ease.

A job I applied to gave me an iq test. This was one of the questions.

2x2 matrix

R1C1: A square with 2 Lines behind the square and one line front

R1C2: A square with 2 lines behind.

R2C1: a square with 2 lines front and one behind (mirror of R1C1)

R2C2: ?