Once upon a time, there lived a poor widow and her son Jack. One day, Jackâs mother told him to sell their only cow. Jack went to the market and on the way, he met a man who wanted to buy his cow. Jack asked, âWhat will you give me in return for my cow?â The man answered, âI will give you five magic beans!â Jack took the magic beans and gave the man the cow. But when he reached home, Jackâs mother was very angry. She said, âYou fool! He took away your cow and gave you some beans!â She threw the beans out of the window. Jack was very sad and went to sleep without dinner.
Which sentence states the theme of the passage?