Which country in the world has the largest Muslim Population in the world?

Indonesia

The correct answer is Option 4: Indonesia

NCERT: The Indian nation-state is socially and culturally one of the most diverse 102 countries of the world. It has a population of about 1.21 billion people, according to Census of India 2011, currently the second largest – and soon to become the largest – national population in the world. These billion-plus people speak about 1,632 different languages and dialects. As many as twenty two of these languages have been officially recognised and placed under the 8th Schedule of the Constitution, thus guaranteeing their legal status. In terms of religion, about 80% of the population are Hindus, who in turn are regionally specific, plural in beliefs and practices, and divided by castes and languages. About 14.2% of the population are Muslims, which makes India the world’s second largest Muslim country after Indonesia and Pakistan. The other major religious communities are Christians (2.3%), Sikhs (1.7%), Buddhists (0.7%) and Jains (0.4%). Because of India’s huge population, these small percentages can also add up to large absolute numbers.

Note: there seems to be a printing mistake in the NCERT. India is the third largest Muslim Country after Indonesia and Pakistan.