What forms when water supporting the roof of a cavern drains and the roof falls

Look at the following answer choices and determine which belongs in the both category. testable, can be disproven explains natural phenomena, has evidence to support it prediction, tentative, one or more scientists working together well established, many different scientists working independently, highly reliable

Cells destroy body cells infected by a virus or bacteria.

Cells are adapted to preform specific functions. which of the following terms refers to this capability?