Explanation:

• Purchasing Power Parity is a way of measuring economic variables in different countries so that irrelevant exchange rate variations do not distort comparisons. It states that exchange rates between currencies are in equilibrium when their purchasing power is the same in each of the two countries. This means that the exchange rate between two countries should equal the ratio of the two countries’ price level of a fixed basket of goods and services. 
• On the PPP basis, China is the world’s largest economy in 2018, followed by the United States at 2 and India at 3 position.

Hence only statement 1st is correct.