(A) The archaeological studies are based on the radioactive decay of carbon-14 isotope.
(R ) The ratio of C-14 to C-12 in the animals of plants is the same as that in the atmosphere.
A. If both (A) and (R ) are correct and (R ) is the correct explanation for (A).
B. If both (A) and (R ) are correct but (R ) is not the correct explanation for (A )
C. If both (A) and (R ) are incorrect.
D. If both (A) and (R ) are incorrect.