Answer: B. Wait for at least a few minutes to see if the system pressure rises.
Step-by-step explanation:
The thing to be done after reaching the required recovery vacuum on an appliance is to wait for at least a few minutes to see if the system pressure rises.
Waiting for at least a few minutes to see if the system pressure rises is necessary in order to show if there's still refrigerant that is either in liquid form or probably in the oil.