The pieces in Figure (X) are put together, without overlapping, to make one of the figures given in the options. Which one? (Lines inside an option show its pieces.)

Answer & explanation
Correct answer: option 1
The correct answer is Option (1) →

A figure can be formed from the pieces only if it is cut into exactly the 4 pieces of Figure (X), each with the same shape and size (a piece may be turned round). The 4 pieces of Figure (X), turned round where needed, fit together as the rectangle of Option (1), as shown in the same colours below.

Option (2) — Incorrect. The line between its bottom-right piece and its bottom-left piece is in a different place: the bottom-right piece has one small square less and the bottom-left piece one small square more, so neither of them is one of the given pieces.
Option (3) — Incorrect. The line between its bottom-right piece and its top-right piece is in a different place: the bottom-right piece has half a small square less and the top-right piece half a small square more, so neither of them is one of the given pieces.
Option (4) — Incorrect. It is cut differently: its bottom-left and top-right pieces do not match any piece of Figure (X), even when turned round.