In Type I buildings, what is the only material that is certain to burn?

The correct response focuses on the nature of Type I construction, which primarily consists of non-combustible materials such as concrete and steel. These materials are designed to withstand high temperatures and do not support combustion. Therefore, within a Type I building, the only element that is certain to burn is the contents, which may include furniture, stored materials, and personal belongings. These items can ignite and contribute to the fire's intensity and spread. The structure itself, made from non-combustible materials, is not expected to burn, which emphasizes the distinction between structural components and contents in fire scenarios.