The correct answer is C. As per the 2021 census, the population of Kerala is 35,806,699.
Option A is incorrect because the population of Kerala is much more than 10 million. According to the 2021 census, the population of Kerala is 35,806,699.
Option B is incorrect because the population of Kerala is much more than 20 million. According to the 2021 census, the population of Kerala is 35,806,699.
Option D is incorrect because the population of Kerala is much less than 50 million. According to the 2021 census, the population of Kerala is 35,806,699.