Which of the following materials is likely to contain asbestos?

Insulation is likely to contain asbestos because, historically, asbestos was commonly used in various forms of insulation materials due to its heat resistance and insulating properties. This includes not only traditional thermal insulation found in attics and walls but also pipe insulation and boiler insulation. Many buildings constructed before the 1980s utilized asbestos-containing materials to meet fireproofing and energy efficiency needs.

While other materials such as ceramic tiles or concrete blocks can have some connection to asbestos in certain contexts (like older floors with asbestos backing), they are not primarily known for containing asbestos like insulation is. Plastic sheeting, by its nature, typically does not contain asbestos since it is made from synthetic materials designed for moisture barriers or protective covers. Thus, insulation stands out as the most definitive material among the choices provided in relation to asbestos exposure risks.