There is a Parliamentary System of Government in India because the

The correct answer is D. The defining feature of a parliamentary system is that the executive is drawn from and answerable to the legislature. Under Article 75(3), the Council of Ministers is collectively responsible to the Lok Sabha, so it stays in office only while it commands the House's confidence. Article 74 makes the President act on the Council's advice, which is the Westminster model India adopted.

• A is wrong. Direct election of the lower house is common to presidential systems too, such as the US House of Representatives. It does not define the system.
• B is wrong. The amendment power comes from Article 368. Many constitutions give their legislatures amendment powers, and the power does not tell us the form of government.
• C is factually true, since the Rajya Sabha is a permanent house, but it is irrelevant. That feature belongs to bicameralism and the federal character of the Union. The US Senate is also a continuing body.

This links to GS-II on executive-legislature relations. Lok Sabha confidence votes, no-confidence motions and dissolution are the practical tools that enforce accountability.

Trap: Candidates pick C because a permanent house sounds distinctive. Ask first which feature the executive's accountability depends on.