( D )One place scientists are studying closely is Europa, a moon of Jupiter. Space probes have provided evidence that Europa has alarge ocean under its surface. The probes have also made scientists think that under its surface Europa has a rocky core giving offvolcanic heat. Water and heat from volcanic activity are two basic conditions needed for life to form. A third is certain basicchemicals such as carbon, oxygen, and nitrogen. Comets and meteorites carrying these chemicals have certainly hit Europa at somepoint. So scientists think chemicals might be lying at the bottom of Europa ’s ocean. They may have already created life --- or may beabout to. 53. According to the passage, life may have already exist in Europa because
(A)Europa has an active volcano giving of volcanic heat.
(B) Europa is often hit by comets and meteorites.
(C) The soil on Europa is rich in carbon, oxygen, and nitrogen.
(D)Three basic conditions for life to form are all found in Europa.