Correct option is C
Replace “populated” given in the sentence with “populous” to make it grammatically and contextually correct.
• "Populated" refers to the existence of people in an area.
• "Populous" emphasizes the high numbers or density of people in that area.
• For example, "India is a populous country" emphasizes the fact that there are many people living in India.
• While "The Amazon rainforest is sparsely populated" emphasizes the fact that there are relatively few people living in that region.