Exp) Option d is the correct answer.

With reference to the government in India, the two terms namely “Union of India” and “Territory of India” have specific meanings. ‘Union of India’ stands for the states that share federal powers with the Union Governments, but Territory of India include not only the states but all other units like the Union Territories. In other words, the territory of India includes a larger area as compared to the union of India. i.e., the territory of India covers the entire territory over which Indian sovereignty is exercised while Union of India covers only the federal system.

Option a is incorrect. According to Dr. B.R. Ambedkar, the phrase ‘Union of States’ has been preferred to ‘Federation of States’ for two reasons: one, the Indian Federation is not the result of an agreement among the states like the American Federation; and two, the states have no right to secede from the federation. The federation is an Union because it is indestructible. The country is an integral whole and divided into different states only for the convenience of administration

Option b is incorrect. Article 1 of Constitution mentions India as union of States. Article 1 also mentions what constitutes as Territory of India. According to which territory of India shall comprise of- (a) The territories of the States; (b) The union territories as specified in the First Schedule; and (c) Such other territories as may be acquired.

Option c is incorrect. The ‘Territory of India’ is a wider expression than the ‘Union of India’ because the latter includes only states while the former includes not only the states, but also union territories and territories that may be acquired by the Government of India at any future time.