Assertion `(A) : ` Nuclear isomers have same atomic number and same mass number but with different radioactive properties.
Reason `(R) : U_((A))` and `U_((Z))` are nuclear isomers.
A. If both `(A)` and `(R)` are correct , and `(R)` is the correct explanation of `(A)`
B. If both `(A)` and `(R)` are correct, but (R) is not the correct explanation of `(A)`
C. If `(A)` is correct, but `(R)` is incorrect.
D.
