To answer this question, we need to have knowledge about the characters and relationships mentioned in the epic Ramayana.
Option A) The mother of Ravana - This option is correct. According to Ramayana, Kaikasi is indeed the mother of Ravana, who is one of the main antagonists in the story.
Option B) The mother of Kaikeyi - This option is incorrect. Kaikeyi is one of the wives of King Dasharatha and the mother of Bharata, not the mother of Ravana.
Option C) The sister of Kausalya - This option is incorrect. Kausalya is one of the wives of King Dasharatha and the mother of Lord Rama, not the sister of Kaikasi.
Option D) The daughter of Mareecha - This option is incorrect. Mareecha is a character in Ramayana who was a rakshasa (demon) and a follower of Ravana. Kaikasi is not mentioned as his daughter.
Therefore, the correct answer is A) the mother of Ravana. Kaikasi is depicted as the mother of Ravana in the epic Ramayana.