Option a is the correct answer. Ramachandra Dev, also known as Ramadeva, was the ruler of Devagiri at the time of Alauddin Khalji's invasion. He was a ruler of the Seuna (Yadava) dynasty in the region. Initially, he resisted Muslim invasion and selfishitude to Alauddin Khalji in 1296 C. He given after discontinuing the tribute payments, he was subjugated by Alauddin's army led by Malik Kafur around 1308, becoming a vassal of the Delhi Sultanate. Subsequently, Ramachandra served Alauddin as a loyal feudatory, and helped his forces defeat the Kakatiyas and the Hoysalas.