Let's evaluate each statement based on 2001 census data and demographic terms: A) "Today nearly 28% of India's population resides in towns." As per the 2001 Census, the urban population was 27.8%, which is nearly 28%. This statement is TRUE. B) "The year 1921 is the urban divide in the demographic history of India." 1921 is known as the "Year of Great Divide" in India's demographic history, marking the point after which India's population began to grow steadily, unlike the erratic growth before due to famines and epidemics. While this impacted overall population and indirectly urban population, the term "urban divide" specifically for 1921 is not standard demographic terminology. However, compared to statement D, it might be considered less definitively false or an unusual phrasing rather than a factual error. C) "Mumbai is the most populous metropolis of India." As per the 2001 Census, the Mumbai Urban Agglomeration was indeed the most populous urban agglomeration in India. This statement is TRUE. D) "There are only 5 million cities in Uttar Pradesh." A 'million city' typically refers to an urban agglomeration or city with a population of 1 million or more. As per the 2001 Census data, Uttar Pradesh had more than 5 such urban agglomerations/cities. The million- plus UAs/cities in UP in 2001 included Kanpur, Lucknow, Agra, Varanasi, Meerut, Allahabad, and Ghaziabad. This is a total of 7. Therefore, the statement that there are only 5 million cities is FALSE. Given that the question asks for the statement that is not true, statement D is factually incorrect based on the 2001 census figures. Statement B is also arguably not precisely true in standard terminology, but D provides a specific, verifiable incorrect number of cities.