The correct answer is c) Kollam.
Kollam is the leading district in mineral sand mining in Kerala. It accounts for about 60% of the total mineral sand production in the state. The main types of mineral sands found in Kollam are rutile, ilmenite, and zircon. These minerals are used in a variety of industries, including the manufacture of ceramics, glass, and paint.
Ernakulam is the second largest district in Kerala in terms of population and area. It is located in the central part of the state and is home to the city of Kochi, the commercial capital of Kerala. Ernakulam is not a major producer of mineral sands.
Alappuzha is a district in the south of Kerala. It is known for its backwaters and is a popular tourist destination. Alappuzha is not a major producer of mineral sands.
Kasaragod is a district in the north of Kerala. It is the northernmost district in the state and is located on the border with Karnataka. Kasaragod is not a major producer of mineral sands.