Which of the following vehicles can carry the highest number of litter patients?

The CH-47 Chinook is specifically designed as a heavy-lift helicopter, which allows it to carry a significant payload, including multiple litter patients. This versatile aircraft is equipped with a spacious cabin and has the capability to accommodate stretchers and medical personnel, allowing for efficient aeromedical evacuation of patients in need of urgent care.

The Chinook's dual-rotor design not only provides stability but also allows it to operate effectively in a variety of environments, making it ideal for rapid patient transport in military and emergency situations. The large internal space and ability to adapt for multiple configurations further enhance its capacity for carrying a higher number of litter patients compared to the other vehicles listed.

In contrast, while the RG33 HAGA MRAP and the M-113 Armored Ambulance have their own functionalities and can transport patients, they do not offer the same level of capacity or flexibility in terms of patient transport as the Chinook. The UH-1H/V Iroquois, commonly known as the Huey, is also a capable air ambulance but is limited in the number of patients it can carry compared to the Chinook. Thus, the Chinook stands out as the vehicle capable of carrying the highest number of litter patients.