When is it permissible for a pilot to carry passengers for compensation?

A pilot must hold a valid commercial pilot certificate in order to carry passengers for compensation. This requirement is rooted in aviation regulations that specify the conditions under which a pilot can earn money while operating an aircraft. Only pilots with this higher level of certification are trained in the complexities of conducting commercial operations safely and effectively.

While the pilot's ownership of the aircraft or whether the passengers are paying might seem relevant, they do not change the fundamental requirement for a commercial pilot license. Option D accurately captures the prohibition against private pilots engaging in commercial operations, thus reinforcing the importance of proper licensing and adherence to aviation safety rules.