Which of the following conditions would indicate that the liquid line strainer in a refrigeration system has become excessively restricted and requires cleaning or replacement?

Correct Answer: Option A — Noticeable temperature drop between the strainer inlet and the outlet tubing.

A restricted liquid line strainer creates a localized pressure drop across the restriction. Because of the pressure drop, a portion of the liquid flashes into vapor, producing a noticeable temperature drop detectable by touch between inlet and outlet tubing.