Practice question

Correct option is C, Opening acetylcholine-sensitive K+ channels. In Cardiovascular System: Heart, the accurate description is Opening acetylcholine-sensitive K+ channels, 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 Opening acetylcholine-sensitive K+ channels does in Cardiovascular System: Heart. Then Opening acetylcholine-sensitive K+ channels 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 Opening acetylcholine-sensitive K+ channels.