How many passenger mask couplings are installed on the portable O2 bottle?

The correct answer is that there are two passenger mask couplings installed on the portable O2 bottle in the Dassault Falcon 7X. This design allows for adequate oxygen delivery options to more than one passenger in the event of cabin depressurization or an emergency. By having two couplings, it ensures that both the pilot and copilot can easily distribute the oxygen masks to passengers when necessary, promoting safety and efficiency in emergency situations. Having multiple couplings also enhances the likelihood that each passenger can receive oxygen without delays, which is critical in time-sensitive scenarios.

The other options do not represent the actual number of couplings on the portable O2 bottle, thus highlighting the importance of understanding the specifications of the aircraft's oxygen system to ensure proper emergency response protocols.