heartbeat（心跳） the slowest

Q) Yu does four activites, During which acitivity will his heartbeat（心跳） the slowest?
......B

A) Beating a drum(不停打鼓）
B) Drawing a picture of a dinosaur（恐龙）
C) Playing soccer(英式足球)
D) Jogging around the park（在公园慢跑 ）