How many countries of the world have adopted compulsory voting system?

The answer is D (22). Compulsory voting means citizens must turn out at elections, and sanctions such as fines or penalties may follow for abstention. Commonly cited comparative data put the number of countries where it is actually enforced at about 22, and Australia, Belgium and Brazil are the usual examples.

• A (32): This figure is sometimes quoted for countries where compulsory voting exists in law, but many of these laws are not enforced. It is not the usual count for enforced systems.
• B (25) and C (24): These are not the standard figures in comparative politics sources for this question.

The core concept is the difference between compulsory voting and the right to abstain. India has no compulsory voting. Its voters can abstain, and the 2013 introduction of NOTA after the PUCL judgment gave voters a way to reject all candidates without abstaining. Article 326 provides adult suffrage, and the Representation of the People Act, 1951 governs elections. Compulsory voting is a recurring theme in electoral reform debates, and a Mains answer can weigh turnout gains against individual liberty.

Trap: Aspirants mix up 'legally provided' with 'actually enforced' and pick 32 without checking the wording of the question.