The correct answer is option D, Elephant.

Explanation:
The Constituent Assembly of India, which was responsible for drafting the Constitution of India, adopted the emblem of an elephant as its symbol in 1947.

Here are some reasons why the elephant was chosen as a symbol:

1. Significance in Indian culture: Elephants have been an important part of Indian culture and history for centuries. They are revered as symbols of strength, wisdom, and prosperity.

2. Unity in diversity: Elephants are found in many parts of India and are respected by people of different religions, castes, and communities. Similarly, the Constituent Assembly aimed to create a Constitution that would unite the diverse people of India.

3. Constitutional values: Elephants are known for their loyalty, courage, and sense of responsibility. These are also values that are important for a strong and effective Constitution.

4. Historical connection: The elephant has also been associated with the Maurya Empire, which was one of the greatest empires in ancient India. The Mauryan Emperor Ashoka used the image of four elephants standing back-to-back as the symbol of his reign.

In conclusion, the elephant was chosen as a symbol of the Constituent Assembly because of its significance in Indian culture, its ability to represent unity in diversity, its association with important constitutional values, and its historical connection to ancient India.