What evidence supports a scientist's conclusion that fossil b is older than fossil a? a. fossil a and fossil b were both found at the same depth below earth's surface. b. fossil b was found at a depth of 185 meters below earth's surface, while fossil a was found at a depth of 50 meters below earth's surface. c. fossil b was found at a depth of 50 meters below earth's surface, while fossil a was found at a depth of 185 meters below earth's surface. d. fossil a was found below earth's surface, while fossil b was found at surface level.