Answer: B. 180°.
Step-by-step explanation: In the attached figure, GHIJ is a square and ABCDEF is a regular hexagon having common centre O.
A square is symmetric at a rotational angle of 90° and a regular hexagon is symmetric at a rotational angle of 60°.
So, to bring the image of the square and the hexagon back to the previous position, we need to find the LCM of both the angles.
LCM(60°,90°)=180°.
So, the correct option is B. 180°.
