Answer
Please see the work below.
Work Step by Step
(a) We know that carbon-14 gives useful results for dating specimens about 45,000 years old. It is useful for dating organic materials (for example, human and animal remains, pottery and paper, etc).
(b) We know that carbon dating is not useful for dating inorganic materials, for example rocks, for some organic material like fossils, which are millions of years old and inorganic carbon in the shell etc.