Select the correct option to fill blank 4.
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. more.
- The most appropriate option is "more" because it correctly conveys that yawning is believed to help increase the amount of oxygen intake.
- The use of "more" suggests that the act of yawning is associated with a need for a greater quantity of oxygen, aligning with the explanation given in the passage.