The correct answer is option 1, the Attorney General of India. The Attorney General of India is the highest-ranking law officer of the government and is appointed by the President. Although not a member of either House of Parliament, the Attorney General can attend the meetings of both Houses and participate in their discussions. This is because the Attorney General provides legal advice to the government and represents the government in legal matters. In this role, it is important for them to have an understanding of the proceedings and debates in both Houses of Parliament.

Option 2, the Comptroller and Auditor General of India, while an important constitutional position, does not have the authority to attend meetings of either House of Parliament. The Comptroller and Auditor General is responsible for auditing government accounts and ensuring financial transparency and accountability.

Option 3, the Solicitor General of India, is a law officer who assists the Attorney General. Similar to the Attorney General, the Solicitor General does not have the authority to attend meetings of either House of Parliament.

Option 4, the Vice President of India, is the ex-officio Chairman of the Rajya Sabha, the upper house of Parliament. While the Vice President plays a crucial role in the functioning of the Rajya Sabha, they do not have the authority