Which set of quantum numbers $(n, l, m)$ is forbidden?

The set of quantum numbers $(n, l, m)$ is forbidden are 1, 1, 0.

The quantum number I must be smaller than n, which it is not, even if the quantum number n is an integer. This means that certain quantum numbers are not permitted. Although n, the fundamental quantum number, is an integer, l cannot be negative. Therefore, this set of quantum numbers is not permitted.

Hence, the option D is correct.