Jimmy saw the time while going to the tennis court. He saw the hour hand is 20° away from 4. After he returned from tennis court, he noticed that the hour hand is 20° away from 4. If he took ten minutes to go to tennis court and he walked at the same speed while going to the tennis court and while returning, how much time did he spend at the tennis court?

• A. 60 minutes
• B. 80 minutes
• C. 70 minutes
• D. 50 minutes