Plateau phase of ventricular action potential is due to:
Go with C — Ca2+ influx with reduced K+ efflux. Within Cardiovascular System: Heart, that statement lines up with the standard definition and the usual exam wording you’ll see. In plain terms, cause and effect line up with Ca2+ influx with reduced K+ efflux — that is the mechanism or reason the stem is pointing to. Holding that picture in mind makes Ca2+ influx with reduced K+ efflux feel natural rather than something you only memorise. Link the term to a real body example (organ, tissue, or ion flow) so the idea stays concrete under exam pressure. A short mental diagram helps — start from stimulus or structure, follow the pathway, and stop at the functional result described by Ca2+ influx with reduced K+ efflux.
Ref: Animal physiology is Unit 7 of the CSIR NET Life Science Syllabus, covering core body systems. It accounts for roughly 10% of the total marks in Sections B and C.