A researcher discovers a fossil of what appears to be one of the oldest-known multicellular organisms. The researchers could estimate the age of this fossil based on
a) the amount of carbon-14 in the fossil.
b) the amount of uranium-238 in the fossil.
c) the amount of carbon-14 in the sedimentary rocks in which the fossil was found.
d) he amount of uranium-238 in volcanic layers surrounding the fossil.
e) the amount of uranium-238 in the sedimentary rocks in which the fossil was found.
