Question 107Refrigeration & AC - QMED

The correct answer is C) a liquid line restriction. Frosting or sweating of a liquid line is typically indicative of a restriction in the liquid line, which causes a drop in pressure and temperature. This drop in temperature can lead to condensation and freezing of moisture on the outside of the line. Other causes, such as high relative humidity (A) or refrigerant contamination (B), may contribute to the issue but are not the primary reason for the frosting or sweating. Proper cooling (D) would not result in this condition, as the liquid line should maintain a consistent temperature without restrictions.