Research indicates that yawning is:
A)caused by an overproduction of carbon dioxide in the body.
B)not contagious.
C)caused by too little oxygen in a person's blood.
D)generally followed by an increase in activity level.

Question

Quizplus · Accepted Answer

Research suggests that yawning is often followed by an increase in alertness and activity level, possibly due to its role in regulating brain temperature and promoting wakefulness.

Research Indicates That Yawning Is