My recommendation is Armor Clad for Health Care Facilities (AC-HCF).
Reprinted from the link below: Aluminum Armor Clad for Healthcare Facilities (AC-HCF) is the best choice for Isolated Ground A/V systems. Like MC, it contains an additional grounding conductor, although with this type of cable it is permissible to use the metal jacket as the safety grounding conductor, as required with isolated ground installations. The biggest benefit is that the average proximity of the hot conductor and the neutral conductor with respect to the isolated equipment grounding conductor is nearly equal, virtually eliminating ground voltage induction (GVI), even on long runs.
You could use the red conductor as an isolated ground, but it should be marked with green tape in the circuit breaker box.
See Middle Atlantic’s page 12.
Optimized Power Distribution and Grounding for Audio