Which figure from the options completes the figure matrix below?

Answer & explanation
Correct answer: option 4
The correct answer is Option (4) →
In each row, the third figure is the first two figures put together, but a line that is in both of them disappears. Doing the same with the first two figures of row 3 gives the missing figure.

Why the other options are incorrect
Option (1) — Incorrect. It keeps the line that is in both the first and the second figure; that line should disappear.
Option (2) — Incorrect. It has an extra line that is in neither of the first two figures.
Option (3) — Incorrect. One line of the correct figure is missing.