Correct Answer: United Kingdom

Solution : As per the given graph:
For the World,
The change in the rate of inflation in the World = $\frac{16-14.6}{14.6}×100$
The change in the rate of inflation in the World = 9.58%
For the Developed nations,
The change in the rate of inflation in the Developed nations = $\frac{14.2-11.8}{11.8}×100$
The change in the rate of inflation in the Developed nations = 20.34%
For the United Kingdom,
The change in the rate of inflation in the United Kingdom = $\frac{23.5-21.7}{21.7}×100$
The change in the rate of inflation in the United Kingdom = 8.29%
For the Third World,
The change in the rate of inflation in the Third World = $\frac{36.2-26.6}{26.6}×100$
The change in the rate of inflation in the Third World = 36.09%
The change in the rate of inflation was the least in the United Kingdom.
Hence, the correct answer is the United Kingdom.