Which of the following words is NOT mentioned in the Preamble of the Constitution of India ?

The Preamble of the Constitution of India declares India to be a Sovereign Socialist Secular Democratic Republic. Among the options provided, the word 'Federal' is NOT mentioned in the Preamble. Although the Indian Constitution establishes a federal system, the word 'Federal' does not appear in the Preamble or even in the main text of the Constitution (Article 1 describes India as a 'Union of States'). The words 'Socialist' and 'Secular' were added to the Preamble by the 42nd Constitutional Amendment Act, 1976. The Preamble serves as an introduction to the Constitution and sets out the main objectives of the Indian State, including Justice, Liberty, Equality, and Fraternity.