By elimination: Cheetal (Spotted Deer) is least concern/common species. Blue Bull (Nilgai) is also common. Hanuman Langur is not endangered. Rhesus Monkey is not endangered. Option A — Great Indian Bustard (critically endangered), Musk Deer (endangered), Red Panda (endangered/vulnerable), Asiatic Wild Ass (near threatened/vulnerable) — all are conservation concern species. This is the best option as it contains the most legitimately threatened species. Great Indian Bustard is a Critically Endangered species; Snow Leopard is also an endangered specie.