Question 21Refrigeration & AC - QMED

The correct answer is C) both liquid and vapor. The push-pull technique can be used to recover both the liquid and vapor refrigerant from a refrigeration system. This technique involves pushing the liquid refrigerant out of the system, followed by pulling the remaining vapor refrigerant. It is an effective method for recovering refrigerant from the system, regardless of whether it is in a liquid or vapor state. The other answer choices are incorrect because option A) would be too limited, as the push-pull technique can recover both liquid and vapor, and option D) is incorrect, as the push-pull technique can be used with low-pressure systems as well.