The correct answer is (a) Saharia.
The Saharia are an indigenous people of India who live in the states of Rajasthan, Madhya Pradesh, and Uttar Pradesh. They are estimated to number around 1.5 million people. The Saharia are a tribal people who have a distinct culture and language. They are traditionally hunter-gatherers and farmers.
The Tharu are an indigenous people of India who live in the Terai region of the Himalayas. They are estimated to number around 1.2 million people. The Tharu are a tribal people who have a distinct culture and language. They are traditionally farmers and herders.
The Agaria are an indigenous people of India who live in the states of Madhya Pradesh, Chhattisgarh, and Jharkhand. They are estimated to number around 1 million people. The Agaria are a tribal people who have a distinct culture and language. They are traditionally iron smelters and blacksmiths.
The Mahigir are an indigenous people of India who live in the states of Uttar Pradesh, Madhya Pradesh, and Chhattisgarh. They are estimated to number around 500,000 people. The Mahigir are a tribal people who have a distinct culture and language. They are traditionally fishermen and farmers.
The Saharia have the highest population of the four tribes mentioned. They are estimated to number around 1.5 million people. The Tharu have a population of around 1.2 million people. The Agaria have a population of around 1 million people. The Mahigir have a population of around 500,000 people.