Answer:
rotational symmetry
Explanation:
a line symmetry is, when you can put a line in, and whatever you see in one side of the line is mirrored on the other side of the line.
this is not the case here.
the rotational symmetry is, when you rotate the whole thing by a part of a full circle, and it looks the same again.
this is the case here by every 90°.
with every 90° rotation the object looks like at the beginning.
therefore, this is the right answer.