Which of the following best describes the action of Rohypnol?

Rohypnol, also known as flunitrazepam, is a sedative that is primarily known for its potent muscle relaxant properties and its ability to decrease inhibitions in users. When taken, it acts on the central nervous system, producing calming effects that can lead to drowsiness, relaxation of muscles, and an overall reduction in anxiety and inhibitions. This makes option B the most accurate choice, as it specifically highlights both muscle relaxation and the reduction of inhibitions, which are hallmark effects of Rohypnol.

In contrast, options like enhancing alertness and concentration or increasing energy and performance do not align with the pharmacological effects of Rohypnol, which actually promotes sedation rather than stimulation. Furthermore, stating that it has no effect on the central nervous system is incorrect, as Rohypnol is a powerful CNS depressant. Therefore, the accurate description revolves around its ability to induce muscle relaxation and diminish inhibitions, which is well-captured by the correct answer.