Correct answer: (b) 4 3 1 2
Explanation
- A
4 3 2 1
Code 4 3 2 1 would put Nandadevi in Meghalaya and Nokrek in Uttarakhand. Nandadevi is in Uttarakhand and Nokrek in Meghalaya, so this code swaps the last pair.
- B
4 3 1 2
Code 4 3 1 2 is Similipal–Odisha, Pachmarhi–Madhya Pradesh, Nandadevi–Uttarakhand, Nokrek–Meghalaya. All four UNESCO biosphere locations match, so (b) is the official key.
- C
1 3 4 2
Code 1 3 4 2 would send Similipal to Uttarakhand and Nandadevi to Odisha. Both Himalayan and Eastern Ghats assignments collapse.
- D
3 4 1 2
Code 3 4 1 2 starts Similipal in Madhya Pradesh and Pachmarhi in Odisha—the two central-eastern sites reversed.
Summary. Official key is (b) 4 3 1 2. Similipal is Odisha’s tiger and biosphere landscape; Pachmarhi is the Satpura biosphere in Madhya Pradesh; Nanda Devi is the Uttarakhand Himalayan biosphere; Nokrek is the Garo Hills biosphere in Meghalaya. Honour the stored letter (b).