Answer: The given statement is true.
Step-by-step explanation:
It is known that when we get enough sleep then we feel refreshed. Also, sleeping for 8 to 9 hours helps in the improvement of health of a person because more we sleep more our mind remains relaxed.
As a result, we feel good, happy and delighted. Therefore, we are able to focus on our goals with more concentration.
Thus, we can conclude that the statement for most people, getting 8 to 9 hours of sleep increases concentration, improves physical health, and improves one's mood, is true.