Final answer:
Succinylcholine is the drug used for rapid muscle relaxation during short operative cases. It is known for its quick onset and short action duration, making it suitable for procedures requiring swift muscle relaxation.
Step-by-step explanation:
The drug used for rapid muscle relaxation in short operative cases is B) Succinylcholine. Succinylcholine is a depolarizing skeletal muscle relaxant, which is an important part of the medication regimen during general anesthesia. It is favored due to its rapid onset and short duration of action. When administered as an injection, it provides quick muscle relaxation, facilitating intubation and short surgical procedures. It is distinct from drugs like propofol, which is an induction agent, fentanyl, an opioid analgesic, and midazolam, a benzodiazepine sedative used to induce sedation.