Female voice generally shows higher pitch because of:
Go with C — Higher vocal fold tension. Within Sensory System Ear Physiology, 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 Higher vocal fold tension — that is the mechanism or reason the stem is pointing to. Holding that picture in mind makes Higher vocal fold tension 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 Higher vocal fold tension.
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.