If the running suction pressure at the refrigeration compressor of a TXV controlled air- cooled refrigeration system is below normal, which of the following can be a cause?

Correct Answer: Option C — a restricted liquid-line strainer

A restricted liquid-line strainer impedes refrigerant flow to the thermostatic expansion valve, starving the evaporator and reducing mass flow rate, which causes suction pressure to drop below normal operational parameters.