Given below are two statements, one is labelled asAssertion (A) :and the other as Reason (R).Assertion (A):Voices of men and women are different.Reason (R):Length and thickness of vocal cord is different in men and women.

1. A

   Both (A) and (R) are true, but (R) is not the correct explanation of (A)

   Both true, R not explaining A. Cord length and thickness are exactly why pitch differs.

2. B

   (A) is false, but (R) is true

   (A) false. Male and female voices do differ on average.

3. C

   (A) is true, but (R) is false

   (R) false. Vocal folds differ in length and mass/thickness.

4. D

   Both (A) and (R) are true and (R) is the correct explanation of (A)

   Both true and R explains A. Different cord length and thickness produce different voices.

Summary. Official key is (d). Voices differ because vocal cords differ in length and thickness. Also note: Male folds — Longer, thicker; lower pitch; Larynx growth — Puberty; Adam’s apple; Frequency — Pitch in hertz; Timbre — Also tract shape; not this reason.