To find out how many more people live in China than in India, we subtract the population of India from the population of China.
China's population: 1.45 × 10^9
India's population: 1,400,000,000
China's population - India's population = 1.45 × 10^9 - 1,400,000,000
= 50,000,000
= 5 × 10^7
Therefore, the correct answer is D. 5 x 10^7.