What is the maximum number of passengers a private pilot can carry?

A private pilot is allowed to carry as many passengers as the aircraft's seating capacity permits, as long as those passengers are not being carried for hire or compensation. Therefore, the correct answer indicates that a private pilot can carry one or more passengers, provided that the aircraft is not exceeding its maximum weight limits and is equipped to handle the number of occupants safely.

It's important to differentiate this from the other options. The answer indicating zero passengers is incorrect since private pilots can carry passengers, and the option specifying two or more is too restrictive since carrying just one passenger is also permissible. Lastly, while the answer regarding certification by the aircraft is relevant to overall operational limits, it does not specifically define the maximum number of passengers that a private pilot can carry under standard regulations. Thus, the selection highlighting one or more passengers correctly encompasses the allowances made under FAA regulations for private pilots.