What is a requirement for carrying passengers in a single-engine aircraft at night or under IFR?

Carrying passengers in a single-engine aircraft at night or under Instrument Flight Rules (IFR) necessitates specific pilot qualifications and aircraft conditions. One key requirement is that the pilot must have authorization to carry passengers under these conditions, which indicates that they are compliant with the necessary regulatory, training, and proficiency standards.

This authorization reflects the pilot's competence in managing the complexities and risks associated with night flying or IFR operations. For instance, flying at night presents unique challenges such as limited visibility and increased reliance on instruments, making it crucial for pilots to have experience and training. When a pilot is authorized, it implies that they have undergone the requisite assessments and training to ensure passenger safety during these operations.

The other choices focus on provisions that either do not align with regulatory requirements or present misconceptions about the capabilities of single-engine aircraft regarding night flying and IFR. Therefore, ensuring that the pilot is authorized appropriately is the correct requirement for carrying passengers under the specified conditions.