Please help ASAP!! Choose the correct words to complete the sentences to explain controller systems.

An inverter air conditioning system controls the efficiency at which the compressor runs. It's an example of a/an_
system. On the other hand, a thermostat is an example of a/an_system.

First blank
1) on off controller
2) PID controller
3) statistic process controller

Second blank
1) on off controller
2) PID controller
3) statistic process controller