The correct answer is A. Brahmdeo.
Brahmdeo was the first ruler of the Ratanpur Kalchuri branch in Raipur. He was a descendant of the Kalachuri dynasty, which ruled over parts of central India from the 7th to the 13th centuries. Brahmdeo founded the Ratanpur branch of the dynasty in the 12th century. He was a powerful ruler and expanded his kingdom to include much of present-day Chhattisgarh. Brahmdeo was succeeded by his son, Ramchandra, who continued to expand the kingdom. The Ratanpur Kalchuri dynasty ruled over Raipur until the 16th century, when they were overthrown by the Mughals.
Option B, Ramchandra, was the second ruler of the Ratanpur Kalchuri branch in Raipur. He was the son of Brahmdeo and succeeded him to the throne in the 13th century. Ramchandra was a powerful ruler and expanded his kingdom to include much of present-day Chhattisgarh. He was succeeded by his son, Mohan Singh.
Option C, Mohan Singh, was the third ruler of the Ratanpur Kalchuri branch in Raipur. He was the son of Ramchandra and succeeded him to the throne in the 14th century. Mohan Singh was a powerful ruler and expanded his kingdom to include much of present-day Chhattisgarh. He was succeeded by his son, Ajit Singh.
Option D, Ajit Singh, was the fourth ruler of the Ratanpur Kalchuri branch in Raipur. He was the son of Mohan Singh and succeeded him to the throne in the 15th century. Ajit Singh was a powerful ruler and expanded his kingdom to include much of present-day Chhattisgarh. He was succeeded by his son, Prithviraj Singh.
Option E, None of the above, is incorrect because Brahmdeo was the first ruler of the Ratanpur Kalchuri branch in Raipur.