Selective drugs can block the receptors of any location.

Selective drugs are designed to target specific receptors associated with particular physiological responses, which means they do not block receptors at every location throughout the body. The principle behind selective drug action is to minimize side effects by avoiding interactions with non-target receptors. Therefore, the statement that selective drugs can block the receptors of any location is inaccurate; selective drugs specifically choose which receptors to affect based on their chemical structure and the therapeutic goal. This selectivity allows for more precise treatment of conditions without broadly affecting other systems or receptors in the body. Hence, the correct answer is that it is false to claim that selective drugs block receptors at any location.