Oysters Are an Invertebrate the Lives Today in Brackish Waters

Multiple Choice

Oysters are an invertebrate the lives today in brackish waters along coastal zones.When a geologist working in stratified rocks observes a limestone bed with oyster fossils overlain by beds with clam and echinoderm fossils indicative of marine conditions,the fossils probably indicate ________.

A) the oysters went extinct while these rocks were being deposited
B) the oysters evolved into clams and echinoderms
C) the environment changed as sea level rose,displacing the oysters environment with marine conditions represented by the clams and echinoderms
D) There is not sufficient information to reach any conclusion from these observations.