Wayne hung out with his friends last Saturday. First, they drove 7.8 kilometres to go play miniature golf. From there, they drove 7.1 kilometres to go to a baseball game. Then they drove 5.8 kilometres to the park. How many kilometres did Wayne and his friends drive in all?

• A. 21cm                          
• B. 20.7km 
• C. 0.27cm                       
• D. 2.7cm