There is no object with order of rotational symmetry as 0

So we want to know is there an object with order of rotational symmetry of 0. The order of symmetry is a number of times an object or a shape can be rotated so it still looks like before it was rotated. To find the degree of rotation we need to divide one full rotation that is 360 degrees by at least 2 and we get 180 degrees. If we divide 360 by 1 it would mean the object has to be turned back to it's original position and that means it doesn't have rotational symmetry. If we divide by 0 we get infinity, and infinity isn't a defined number. So there is no object with order of rotational symmetry 0. 

Ithink your answer is b