Scientists Are Now Targeting Europa,one of Jupiter's Moons,as a Likely

Scientists are now targeting Europa,one of Jupiter's moons,as a likely site to search for elementary life forms because

A) there is strong evidence for liquid water beneath the thick ice layer on its surface.
B) large amounts of dark organic material appear to be spread on its surface.
C) changes have been seen in the dark lines crossing the icy surface that have the spectral signature of vegetation.
D) a methane atmosphere suggests life forms currently living there.