Which of the following is a characteristic of mesothelioma?

Mesothelioma is a type of cancer that primarily develops in the mesothelium, which is the thin layer of tissue that covers several organs within the body, notably the lungs, heart, and abdomen. This characteristic is essential in understanding the disease, as it indicates how and where this type of cancer typically arises. The mesothelium serves as a protective lining, and when mesothelioma develops, it affects this crucial tissue, disrupting normal organ function and leading to various symptoms.

The other options do not accurately reflect the nature of mesothelioma. It is known for being quite challenging to treat and typically has a poor prognosis, which makes it not easily treatable. Moreover, it does not primarily affect the digestive system; while it can impact the abdominal region, it is more commonly associated with lung and pleural disease. Additionally, mesothelioma is more prevalent in older adults, particularly those with a history of asbestos exposure, rather than being common among young adults. Thus, the definition and characteristics of mesothelioma strongly support the statement about it affecting the thin lining of multiple organs.