Answer:
A. testing for a disease
Explanation:
Cancer screening is a process that includes checking the body or certain organs for cancer even if there are no symptoms. It means to screen the body or organ to make sure if there is any cancer cell that has not produced symptom, but which can result in more serious illness. Some of the cancers, like breast or cervical cancers, have proven to be less deadly if tests are done on a regular basis.
Yet, as the passage says, most of the time the tests for cancers done on seemingly a healthy person will not help to save a life. Instead, they are promoted even though we are not sure if tests do help at all with battling cancer.
