The correct answer is C) Malappuram.
Malappuram is the most densely populated district in Kerala, with a population density of 1,025 people per square kilometer. It is located in the northern part of the state and is bordered by the districts of Palakkad, Kozhikode, and Wayanad. The district is home to a number of important cities, including Malappuram, Tirur, and Kondotty.
The population of Malappuram has been growing rapidly in recent years. In 2011, the population of the district was 3,745,844. This number is expected to reach 4,500,000 by 2021. The growth of the population is due to a number of factors, including high birth rates, immigration, and natural increase.
The high population density of Malappuram has a number of implications for the district. The district faces challenges such as overcrowding, pollution, and lack of infrastructure. However, the high population density also means that Malappuram has a large workforce and a strong economy.
The other options are incorrect because they are not the most densely populated districts in Kerala.
A) Thiruvananthapuram is the capital of Kerala and is the second most populous district in the state. The population density of Thiruvananthapuram is 800 people per square kilometer.
B) Ernakulam is the commercial capital of Kerala and is the third most populous district in the state. The population density of Ernakulam is 850 people per square kilometer.
D) Thrissur is a major city in Kerala and is the fourth most populous district in the state. The population density of Thrissur is 700 people per square kilometer.