Question ID:PT86 S4 Q12 Passage:The Amazon River flows eastward into the Atlantic Ocean from its source in the western part of South America.  The land through which the Amazon flows is now cut off from the Pacific Ocean to the west by the Andes Mountains.  Yet certain freshwater fish that inhabit the Amazon are descended from now-extinct saltwater fish known to have inhabited the Pacific Ocean but not the Atlantic.  For this reason, some scientists hypothesize that the Amazon River once flowed into the Pacific Ocean. Stem:Which one of the following, if true, provides additional evidence in support of the hypothesis that the Amazon River once flowed into the Pacific Ocean? Correct Answer Choice:BChoice A:In many cases, species of freshwater and saltwater fish that share certain characteristics do not in fact share a common ancestor. Choice B:Most of the fossilized remains of the now-extinct saltwater fish from the Pacific Ocean date to a period prior to the formation of the Andes Mountains. Choice C:Many species of fish that inhabit the Atlantic Ocean are related to fish species that are known to inhabit the Pacific Ocean. Choice D:The Andes Mountains extend from the northernmost to the southernmost extremes of the South American continent. Choice E:There are very few fish species that are known to be able to survive in both fresh and salt water.