The main advantage of the parliamentary form of government is that

Option C is correct. The defining feature of parliamentary government is that the Council of Ministers is collectively responsible to the Lower House (Article 75(3) in India), so the executive can be removed by a no-confidence motion. The main advantage is accountability: the executive must keep the confidence of the legislature and face questions, debates and votes continuously.

• A describes the presidential system, where the executive and legislature are separate and the President has a fixed term. In a parliamentary system they are fused, not independent.
• B is the usual argument for the presidential system's fixed tenure. Parliamentary governments can change policy with shifting majorities and are not automatically more efficient.
• D describes a weakness, not an advantage. The head of government can be changed through the legislature's confidence without a fresh election, which critics cite as a source of instability.

Core concept: responsible government versus stable government. In Mains, the usual angle is to contrast the two systems under Indian Polity and ask whether coalition politics has weakened the accountability feature.

Trap: Students pick B because they associate parliamentary systems with stability or efficiency. Accountability, not stability, is the textbook advantage.