The correct option is D Both Assertion and Reason are incorrect
Inside the larynx are present two pairs of vocal cords. One pair is of
false vocal cords which has little to do with sound production and the
second inner pair is true vocal cords.When air is forced through the.
larynx, it causes vibration of the true vocal cords and sound is
produced. The pitch of sound is determined by the tension on the vocal
cords-the greater the tension, the higher the pitch. So, the correct answer is 'Both Assertion and Reason are incorrect'.