Option c is the correct answer. Rajaraja I was the Chola king who started the naval army and made the Chola empire a maritime power. He ruled from 985 to 1014 CE and was one of the most powerful and influential rulers in Indian history. He conquered the Pandya, Chera, and northern Sri Lanka regions, and extended his influence to the Maldives and Lakshadweep islands. Rajaraja I realized the importance of having a strong navy to protect his coast from foreign invasions and to control the trade routes in the Indian Ocean and the Bay of Bengal. He also wanted to expand his empire to Southeast Asia, where many kingdoms were flourishing. He therefore established a naval army, which was composed of various types of ships, such as merchant ships, warships, patrol boats, etc.