Ascientist publishes a paper that states that changes in the levels of gases in the atmosphere of a moon of saturn indicate that there may be extraterrestrial life on that moon. which statement correctly answers whether the question of alien life on this moon is scientific?

a. the question is not scientific because it cannot be tested without going to the moon of saturn or sending a probe there.
b. the question is scientific because it deals with astronomy.
c. the question is not scientific because it involves alien, extraterrestrial life.
d. the question is scientific because it is testable and verifiable.