Silica sand, an important ingredient in glassmaking, is found in:

Palakkad
Alappuzha
Idukki
Thiruvananthapuram Answer: b

The correct answer is b) Alappuzha.

Silica sand is a type of sand that is composed primarily of silicon dioxide (SiO2). It is an important ingredient in glassmaking, as it is used to create the silica-rich glass that is used in windows, bottles, and other products.

Silica sand is found in many parts of the world, including India. In India, silica sand is found in the states of Andhra Pradesh, Gujarat, Karnataka, Kerala, Madhya Pradesh, Maharashtra, Odisha, Rajasthan, Tamil Nadu, and Telangana.

The largest deposits of silica sand in Kerala are found in the Alappuzha district. The silica sand in Alappuzha is of high quality and is used in the manufacture of glass, ceramics, and other products.

The other options are incorrect because they are not states in India where silica sand is found.