Biosphere reserves are areas comprising terrestrial, marine and coastal ecosystems. Biosphere reserves are nominated by national governments and remain under the sovereign jurisdiction of the states where they are located. Their status is internationally recognised. There are 669 biosphere reserves in 120 countries.
A national park is a park in use for conservation purposes of flora as well as fauna. It is an area of land that is owned and protected by a national government because of its natural beauty or its importance to history or science.
Wildlife sanctuary is a naturally occurring sanctuary, such as an island, that provides protection for species from hunting, predation or competition, it is a protected area, a geographic territory within which wildlife is protected.
So, the correct answer is option C.