14 CFR Part 139 Class I airports may accommodate what type of air carrier operations? Question 5 options: a) Scheduled operations of commercial service aircraft with greater than 9 seats but less than 31 seats b) Only unscheduled operations of commercial service aircraft (including those with greater than 30 seats) c) Scheduled and unscheduled operations of commercial service aircraft with greater than 30 seats d) Scheduled operations of commercial service aircraft with greater than 9 seats but less than 31 seats, and unscheduled operations of commercial service aircraft with greater than 30 seats