Which location houses two air conditioning units (ACs)?

The correct response points to AUX1 as the location that houses two air conditioning units (ACs). AUX1 typically serves as an auxiliary area on a vessel where additional equipment, including HVAC systems, are installed to support the environmental control needs of the ship's internal spaces. By housing two AC units, AUX1 is designed to maintain optimal temperature and air quality, crucial for crew comfort and the proper functioning of electronic and mechanical systems.

Other locations, while they may contain various equipment or systems, do not specifically focus on housing multiple air conditioning units. For instance, AUX2 might have different auxiliary functions or equipment, and the FWD Gen Room is primarily concerned with generator operations rather than climate control. The AFT AC Room specifically focuses on air conditioning but might not have the capacity or design to accommodate two units as stated in the question. Therefore, AUX1 is the most fitting answer based on its design and purpose.