Answer:
The answer is the first option (A): Yawning is a form of communication.
EVIDENCE:
- when the text says, "Other scientists believe, however, that yawning is a form of communication."
- when the text says, "This theory attempts to explain why yawning seems to spread from person to person."
- when the text says, "This kind of behavior is called 'contagious yawning' and carries with it a possible social message."
- when the text says, "Scientists are not yet sure what exactly the message is, but they believe people who have more social empathy are more likely to start yawning when they see someone else yawning."
- and last but certainly not least, when this piece of dialoge is found in the text, "Scientists will continue to investigate the mystery of the yawn. Is it a leftover behavior from before humans had language? Was it a 'Hey, I'm sleepy. Let's go to sleep' message? Or is it really just a way to keep our brains cool?"
Step-by-step explanation:
The first piece of evidence greatly supports the answer by listing one example of one theory which some scientists believe in. The second piece of evidence helps prove that the answer is unerring by stating what the theory is meant to achieve. The third piece of evidence helps verify that the answer is the most precise option by explaining what type of behaviour the theory is meant to discover the meaning of. The fourth piece of evidence confirms that the answer i have selected is most accurate by clarifying that scientists are still attempting to uncover the message spoken by yawning. The fifth and final piece of evidence authenticates the answer's accuracy by questioning the true meaning of the message that is expressed through yawning.