To answer this question, we need to have knowledge about the characters in the Mahabharata and the events that took place during the war.
Option A) Yuyutsu - This option is incorrect because Yuyutsu survived the entire war and even became the ruler of Indraprastha after the war.
Option B) Abhimanyu - This option is incorrect because Abhimanyu, the son of Arjuna, died on the thirteenth day of the war, not on the first day.
Option C) Uttar - This option is correct because Uttar, the son of King Virata, died on the first day of the war. He was killed by Shalya, the ruler of Madra, during their battle.
Option D) Ghatotkacha - This option is incorrect because Ghatotkacha, the son of Bhima, died on the fourteenth day of the war while fighting against Karna.
The correct answer is C) Uttar. Uttar died on the first day of the war.