What does 'air cargo' include?

Air cargo encompasses a variety of items transported through air transportation. The correct answer highlights that it includes both air freight, which refers to goods and commodities shipped via aircraft, and airmail, which involves the shipment of letters and documents. This broad classification is critical in understanding the logistics and operations of airline services that focus on the transportation of goods.

Considering the other options, they each specify a narrow aspect of what air cargo could include but do not encompass the full definition. For example, live animals are part of air cargo, but they represent only a specific segment and not the entirety of air freight services. Similarly, parcels transported via ground are not classified as air cargo since they do not utilize the air transport system. Finally, while passengers' personal luggage is indeed transported by air, it is categorized separately from air cargo, which generally refers to commercial goods rather than personal items. Thus, recognizing that air cargo includes both air freight and airmail allows for a better understanding of the wide-ranging roles airlines play in global logistics.