What are the requirements for carrying passengers as a commercial pilot?

Carrying passengers as a commercial pilot requires a current medical certificate and sufficient flight hours to ensure safety and proficiency in flight operations. The medical certificate is essential because it confirms that the pilot meets the health standards prescribed by the FAA, which is crucial when transporting passengers. Sufficient flight hours ensure that the pilot has enough experience to operate an aircraft safely and effectively, especially in potentially unforeseen situations or emergencies.

While having a valid pilot's license is necessary, it alone does not fulfill the requirement for carrying passengers. Similarly, merely possessing a medical certificate does not address the need for adequate flying experience. The option stating a minimum of flight hours does not provide the full context; the emphasis on both a current medical certificate and substantial experience in flight is what makes option C the correct choice.