Which of the following is an identifying characteristic of an intermodal tank?

An intermodal tank is characterized by its design and construction, which allows it to be easily transported across different modes of transport, such as rail, truck, and ship. The distinguishing feature of an intermodal tank is its box-like steel frame, which provides structural integrity and protection during transit. This frame allows for secure stacking and helps to prevent damage while in transit.

The cylindrical shape is typical for many tanks, including some intermodal tanks, but it is not the defining characteristic that identifies an intermodal tank specifically. Other options, such as construction materials like wood, are unsuitable for safe transport of hazardous materials, as wood can be compromised by liquids and is not typically used in intermodal applications. Additionally, intermodal tanks are not designed to be buried underground, as their primary function is to be transported and made accessible. Thus, the box-like steel frame is the key identifying characteristic that facilitates the unique handling and transport capabilities of intermodal tanks.