According to the passage, which one is irrelevant to the finding of John Burn’s study
A.Aspirin may offer a simple way to control stems cells that make tumors grow.
B.Aspirin may influence the survival of aberrant stem cells in the colon.
C.Aspirin may damage faulty stem cells before their mutation.
D.Aspirin may reduce the risk of developing colon cancer by blocking the COX-2.