Explanation:

- Based on the Census of Foreign Liabilities and Assets of Indian Direct Investment Companies for 2016-17, the countries are ranked by their foreign direct investment inflow into India.

- Option 1: Lists Mauritius, which was the leading source of FDI, last, followed by others, not in the correct order.

- Option 2: Lists Japan with the least FDI but incorrectly structures the order of the rest.

- Option 3: Begins with the UK and Japan with the least, but inaccurately ranks the others.

- Option 4: Suggests Japan, Singapore, the UK, the USA, and Mauritius. This is the correct order, starting with Japan and ending with Mauritius.

The correct order is Option 4: Japan, Singapore, UK, USA, and Mauritius.