In which district of Gujarat, Kachchi language is used as mother tongue?

The correct answer is A. Kutch.

Kachchi is a language spoken in the Kutch district of Gujarat, India. It is a member of the Indo-Aryan language family, and is closely related to Gujarati. Kachchi is spoken by about 2 million people, and is the mother tongue of the Kutchi people.

The other options are incorrect because:

• Mehsan is a district in Gujarat, but Kachchi is not spoken as a mother tongue there.
• Banaskantha is a district in Gujarat, but Kachchi is not spoken as a mother tongue there.
• Dang is a district in Gujarat, but Kachchi is not spoken as a mother tongue there.