Farm in the air

Increasing urbanization has made land a scarce resource in cities. One company in Chongqing made creative use of space by turning its roof into a farm. The company built a farm on the roof of an office building to help its employees relax their minds and bodies. The company employees cultivate rape flowers, lotus root and other vegetables, and even raise some poultry on the farm and can take home the crops at harvest.

The employees are doing activities on the roof EXCEPT for?
A. Planting rape flowers
B. Raising pigs
C. Relaxing their minds

（中國日報網英語點津 杜娟 編輯）