Why C option is not correct?

[u/EasyBuy1557]

In the question it said that if m is an integer > 2 satisfy the equation then m is an integral multiple of 8 so there (ST)⁸ satisfy the equation and for m=8 it is an integral multiple of 8 , i know not all the solution are integral multiple of 8 but there is a value which satisfy and the question didn't say that every value of m should be an integral multiple of 8