The correct answer is D. 1, 2, 3 & 4.
The Seventh Schedule of the Constitution of India lists the subjects that are under the jurisdiction of the Union Government and the State Governments. The Union List includes subjects such as defence, foreign affairs, railways, currency, banking, and customs. The State List includes subjects such as police, public order, local government, education, and agriculture. The Concurrent List includes subjects such as criminal law, marriage and divorce, and labour.
The Armed Forces, Paramilitary Forces, Railway Police, and Cantonment Areas are all Union subjects. This means that the Union Government has exclusive power to legislate on these matters. The State Governments do not have any power to legislate on these matters.
The Armed Forces are the military forces of India. They are responsible for defending India from external aggression and internal threats. The Paramilitary Forces are a group of armed forces that are used to maintain law and order and to deal with internal security threats. The Railway Police is a police force that is responsible for maintaining law and order on the railways. The Cantonment Areas are areas that are set aside for the use of the Armed Forces.
The Union Government has exclusive power to legislate on these matters because they are matters of national importance. The Armed Forces, Paramilitary Forces, Railway Police, and Cantonment Areas are all essential for the security and well-being of India. It is therefore important that the Union Government has the power to ensure that these matters are properly managed.