Which one of the following is not a sub-index of the World Bank’s ‘Ease of Doing Business Index’?

The correct answer is Maintenance of law and order.

The World Bank’s Ease of Doing Business Index was a flagship index that measured business regulations and their enforcement across various countries. It evaluated parameters across different lifecycle stages of a business using 10 primary sub-indices (topics):

1. Starting a Business
2. Dealing with Construction Permits
3. Getting Electricity
4. Registering Property
5. Getting Credit
6. Protecting Minority Investors
7. Paying Taxes
8. Trading Across Borders
9. Enforcing Contracts
10. Resolving Insolvency

Explanation of the Options:
- Paying taxes, Registering property, and Dealing with construction permits are all official sub-indices used by the World Bank to compute the Ease of Doing Business score.
- Maintenance of law and order is a broad governance and national security metric, not a direct sub-index of the Ease of Doing Business Index.

Therefore, Maintenance of law and order is not a sub-index of the World Bank's Ease of Doing Business Index.