A new study has found that the best way to make yourself feel happier is to think of something good that happened to you the day before. Volunteers who were asked to remember a pleasant event from past 24 hours began to feel happier right away.Other activities such as saying "Thank you" and smiling also made volunteers feel happier, but not as much. Professor Richard Wiseman of Hertfordshire University planned the study.He got 26,000 people to go online to try out a few different activities to make them feel happier.They were told to be nice, remember a pleasant event from the day before, give thanks or smile for 15 seconds twice a day.The volunteers did these activities for one week. The result showed that thinking about one good thing that had happened the day before worked the best for making people happier.(146 words) The best title may probably be   _  .
Thinking about yesterday's happiness to be happy today Making a study to make people happier and younger Letting out a secret to live a longer life Doing experiments to make people happier
Question: A new study has found that the best way to make yourself feel happier is to think of something good that happened to you the day before. Volunteers who were asked to remember a pleasant event from past 24 hours began to feel happier right away.Other activities such as saying "Thank you" and smiling also made volunteers feel happier, but not as much. Professor Richard Wiseman of Hertfordshire University planned the study.He got 26,000 people to go online to try out a few different activities to make them feel happier.They were told to be nice, remember a pleasant event from the day before, give thanks or smile for 15 seconds twice a day.The volunteers did these activities for one week. The result showed that thinking about one good thing that had happened the day before worked the best for making people happier.(146 words) The best title may probably be   _  .
A. Thinking about yesterday's happiness to be happy today
B. Making a study to make people happier and younger
C. Letting out a secret to live a longer life
D. Doing experiments to make people happier
Answer: