What system uses compressed air to shuttle objects through a tube?

The correct answer is the pneumatic tube system. This system utilizes compressed air to transport items—typically small packages, documents, or medications—from one location to another through a network of tubes. Pneumatic tubes are commonly found in hospitals and pharmacies for quick and efficient transfer of goods, allowing for a significant reduction in the physical movement required by staff and minimizing the time it takes to deliver important items.

In contrast, a dumbwaiter is a small freight elevator used to transport goods between floors, but it operates using a pulley system rather than compressed air. A crash cart is a mobile cart stocked with medical supplies and equipment for emergency situations, and it does not involve the use of a tube system. A unit dose system refers to the method of dispensing medication in precise, single doses but does not relate to the transportation method described in the question. Understanding the specific function and mechanism of each option clarifies why the pneumatic tube is the right choice in this context.