| What is true concerning frost build-up on the evaporator coils of a multi-box direct expansion refrigeration system? |
| A) the frost can be removed by passing hot gas through the coils or energizing defrost heaters with the evaporator fan shut down |
| B) the frost can be removed by passing hot gas through the coils or energizing defrost heaters with the evaporator fan still running |
| C) the frost will increase the refrigeration effect |
| D) the frost can be quickly removed by simply shutting down the compressor |