What is the most common arrangement for a compact heat exchanger such as that used on an air conditioning cooling coil located in a ventilation supply duct?

Correct Answer: Option B — Finned-tube set up as a serpentine coil.

Finned-tube serpentine coils are standard for HVAC air-cooling applications. The serpentine path ensures the cooling medium traverses the entire coil face, maximizing contact time with the air stream. This design is efficient for compact ventilation ducts where space constraints limit the use of larger shell-and-tube units.