Biosphere reserves differ from National parks or Wildlife sanctuaries because
Humans beings are not allowed to enter
Humans are the integral part of the system
Plants have more attention and care as compared to the animals
Livings organisms were brought all over the world and preserved for posterity
As we have learnt in In-situ Conservation of Biodiversity - Sanctuaries and Biosphere Reserves -
The outermost zone of the biosphere reserve that is the transition zone where sustainable development activities are permitted. This is an area of interaction between the biosphere reserve management and the local people. Here activities such as forestry, recreation, cropping, etc. are permitted.Hence, the correct option is (b).