Is it possible for one multi-split indoor unit to heat while another cools?

The correct response indicates that it is not possible for one multi-split indoor unit to heat while another cools under typical conditions. In a multi-split system, multiple indoor units are connected to a single outdoor unit. Typically, the outdoor unit has a limited ability to provide either heating or cooling at any given time. When one zone (indoor unit) operates in heating mode, the system is configured to redistribute heat removed from the outside air, making it difficult for another zone to operate in cooling mode simultaneously.

The fundamental design of these systems requires that all connected indoor units operate in the same mode—either all in cooling or all in heating—because the outdoor unit can only handle one function at a time. This concept is essential for understanding the limitations of multi-split systems and the efficiency of HVAC operations.

The other options suggest scenarios that imply the capability of providing both heating and cooling simultaneously, which is beyond the operational limits of a standard multi-split system connected to a single outdoor unit.