Which fuel types are prohibited for use in CRJ operations?

The correct choice identifies Jet B and JP-4 as prohibited fuel types for use in CRJ operations. This is important because these fuel types have different characteristics than the recommended Jet A or Jet A-1. Jet B has a much lower flash point and greater volatility, which can pose safety risks during handling and operation in turbine engines. Similarly, JP-4 is a wide-cut fuel that can lead to operational reliability and performance challenges. Using fuels that do not meet the specifications and requirements outlined for a specific aircraft type can adversely affect engine performance, increase possibility of engine failure, and pose serious safety risks. Therefore, it's essential for operators to adhere strictly to approved fuel specifications to ensure safe and efficient aircraft operation.