Practice question

Correct option is B, Passive. In Cardiac Cycle and Regulation, the accurate description is Passive, and that is what you should commit to memory. Keep the definition tight and the role clear — the functional job described in the stem is exactly what Passive does in Cardiac Cycle and Regulation. Then Passive is the answer you can defend. Check yourself by covering the options and writing the answer first, then matching the letter — that builds confidence. If the wording feels dense, translate it into everyday language first, then map that plain sentence back onto Passive. Remember that physiology questions reward precise language: name the process, the location, and the outcome, then match that to the option text.