To answer this question, we need to have knowledge about the characters from the Indian epic Mahabharata.
The correct answer is B) Karna.
Option A) Arjun - Arjuna was one of the five Pandava brothers and the third son of Kunti. He is known for his archery skills and is one of the central characters in the Mahabharata. However, he was not the eldest son of Kunti.
Option B) Karna - Karna was the eldest son of Kunti. He was born to Kunti before her marriage, and he was given away at birth. Karna later became a prominent warrior and fought on the side of the Kauravas in the Mahabharata.
Option C) Bhima - Bhima was the second son of Kunti and was known for his immense strength. He was one of the key warriors among the Pandavas.
Option D) Yudhishtir - Yudhishtira was the eldest among the five Pandava brothers. However, he was not the eldest son of Kunti. He was the son of Kunti's husband Pandu and his first wife, Kunti's sister-in-law, Madri.
Therefore, the correct answer is B) Karna, as he was the eldest son of Kunti.