The Carnatic Wars were a series of conflicts between the British and French for control of:

Northern India
Deccan region
Southern India
Western India

The correct answer is: c) Southern India.

The Carnatic Wars were a series of four wars fought between the British East India Company and the French East India Company in the Indian subcontinent from 1746 to 1763. The wars were fought primarily in the Carnatic region of southern India, which was then under the control of the Mughal Empire. The British and French were both vying for control of the region, which was a major trading center.

The first Carnatic War was fought from 1746 to 1748. The war was sparked by the French capture of the British trading post of Madras. The British responded by capturing the French trading post of Pondicherry. The war ended with the signing of the Treaty of Aix-la-Chapelle, which returned all captured territories to their original owners.

The second Carnatic War was fought from 1749 to 1754. The war was caused by the French attempt to expand their influence in the Carnatic region. The British responded by supporting the Nawab of Arcot, who was opposed to the French. The war ended with the signing of the Treaty of Pondicherry, which returned most of the territories captured by the French to the British.

The third Carnatic War was fought from 1756 to 1763. The war was caused by the French attempt to regain control of the Carnatic region. The British responded by supporting the Nawab of Arcot, who was opposed to the French. The war ended with the signing of the Treaty of Paris, which gave the British control of the Carnatic region.

The Carnatic Wars were a major turning point in the history of British India. The wars gave the British control of the Carnatic region, which was a major trading center. The wars also weakened the Mughal Empire, which allowed the British to expand their influence in India.

The other options are incorrect because they are not the regions where the Carnatic Wars were fought. Option a) Northern India is incorrect because the Carnatic Wars were fought in southern India. Option b) Deccan region is incorrect because the Carnatic Wars were fought in the Carnatic region, which is not part of the Deccan region. Option d) Western India is incorrect because the Carnatic Wars were fought in southern India, which is not part of western India.