Which one of the following statements is not correct?

Which one of the following statements is not correct?

As per the Constitution of India, the Union Council of Ministers is collectively responsible to the Parliament.
Residual Powers are vested in the Parliament.
The President of India is the Constitutional Head of the Executive of the Union.
As per the Constitution of India, there is provision for independence of the Comptroller and Auditor General of India.
This question was previously asked in
UPSC CBI DSP LDCE – 2023
Option A states that the Union Council of Ministers is collectively responsible to the Parliament. As per Article 75(3) of the Constitution of India, the Council of Ministers is collectively responsible to the House of the People (Lok Sabha). While the Lok Sabha is a part of the Parliament, the specific constitutional provision names the Lok Sabha, not the Parliament as a whole. Therefore, stating responsibility to the entire Parliament is not constitutionally precise and is considered incorrect in a strict sense compared to the other options which are correctly stated.
Collective responsibility means that the entire Council of Ministers stands or falls together. If a no-confidence motion is passed against the Council of Ministers in the Lok Sabha, the entire council has to resign.
Option B is correct (Article 248 and Entry 97 of Union List). Option C is correct (Article 53 read with Article 74). Option D is correct (Articles 148-151 ensure the independence of the CAG by providing security of tenure, making his removal difficult, charging his salary on the Consolidated Fund of India, etc.).