The BEST statement that describes how cancers are classified is:
A. Cancers are classified according to the type of tissue they affect.
This is because cancers are typically categorized based on the specific type of tissue or cell from which they originate. For example, there are different types of cancers like lung cancer, breast cancer, or skin cancer, each named after the tissue they affect. This classification helps in determining the appropriate treatment and understanding the behavior of the cancer cells.