There is a Parliamentary System of Government in India because the

1. A Parliamentary System of Government is characterized by the executive branch deriving its democratic legitimacy from and being held accountable to the legislature; the executive and legislative branches are thus interconnected. 2. The defining feature that establishes India as having a Parliamentary System is the principle of collective responsibility, as enshrined in Article 75(3) of the Constitution. 3. Article 75(3) states that "The Council of Ministers shall be collectively responsible to the House of the People (Lok Sabha)". This means the government (the Council of Ministers) remains in office only as long as it enjoys the confidence of the Lok Sabha. This responsibility is the hallmark of a Parliamentary System. Hence, (D) is the correct reason. 4. Option (A) is true (direct election of Lok Sabha) but characteristic of many democratic systems, not exclusively parliamentary ones. 5. Option (B) is true (Parliament's power to amend the Constitution) but relates to the flexibility of the Constitution, not the nature of the executive-legislative relationship. 6. Option (C) is true (Rajya Sabha is a permanent house) but describes a feature of India's bicameral legislature, not the core reason for it being a parliamentary system.