The correct answer is: C) South Kerala.
Thira is a traditional dance form of Kerala, India. It is associated with the Kavus (sacred groves) of South Kerala. The dance is performed by women to propitiate the deities of the Kavus. It is a ritual dance that is performed during the annual festivals of the Kavus. The dance is performed in a circle, with the women holding hands and moving in a clockwise direction. The dance is accompanied by music and singing. The music is played on traditional instruments, such as the chenda, the maddalam, and the edakka. The singing is in praise of the deities of the Kavus. The dance is a beautiful and graceful performance that is a part of the cultural heritage of Kerala.
Option A is incorrect because the Thira dance form is not associated with the Kavus of North Kerala.
Option B is incorrect because the Thira dance form is not associated with the Kavus of Central Kerala.
Option D is incorrect because the Thira dance form is not associated with the coastal regions of Kerala.