The correct answer is: c) Multiple regional languages.
The Census questionnaire is available in multiple regional languages, including English, Hindi, Tamil, Telugu, Kannada, Malayalam, Marathi, Gujarati, Bengali, Oriya, Assamese, Punjabi, and Urdu. This is to ensure that all residents of India can participate in the census and have their voices heard.
Option a) is incorrect because the Census questionnaire is not only available in English and Tamil. It is also available in multiple other regional languages.
Option b) is incorrect because the Census questionnaire is not only available in Tamil and Hindi. It is also available in multiple other regional languages.
Option d) is incorrect because the Census questionnaire is not only available in English. It is also available in multiple other regional languages.