Final answer:
Dantrolene acts on the calcium channels in the skeletal muscle to treat malignant hyperthermia by inhibiting calcium release from the sarcoplasmic reticulum.
Step-by-step explanation:
The student is inquiring about the mechanism of action for dantrolene when used as an IV bolus for treating malignant hyperthermia during surgery. The correct answer to which receptor or channel dantrolene acts upon is B. Calcium channels in the skeletal muscle. Dantrolene works by inhibiting calcium release from the sarcoplasmic reticulum within skeletal muscle cells, thereby reducing muscle contractions and helping to cool and stabilize the body during a malignant hyperthermia crisis.