The correct answer is c) Kollam.
Kollam is the leading district in mineral sand mining in Kerala. The district has a long history of mining, and it is home to a number of large-scale mining operations. The main minerals mined in Kollam are ilmenite, rutile, and zircon. These minerals are used in a variety of industries, including the manufacture of ceramics, glass, and solar panels.
The mining industry is a major contributor to the economy of Kollam. It provides employment for a large number of people, and it generates significant tax revenue for the government. However, the mining industry has also been criticized for its environmental impact. The mining of mineral sands can lead to the destruction of forests and the contamination of water supplies.
The government of Kerala is working to address the environmental concerns associated with mineral sand mining. It has implemented a number of regulations to protect the environment, and it is working to develop sustainable mining practices.
The other options are incorrect because they are not the leading districts in mineral sand mining in Kerala. Ernakulam is a major industrial and commercial center, but it does not have a significant mining industry. Alappuzha is a popular tourist destination, and it is known for its backwaters and beaches. Kollam is a major agricultural and industrial center, and it is home to a number of large-scale mining operations. Kasaragod is a district in the northern part of Kerala, and it is not known for its mining industry.