The audit reports of the Comptroller and Auditor General of India, which pertain to the accounts of the Union, are required to be submitted to a specific authority.

Option 1: The President - This is the correct answer. The audit reports must be submitted to the President of India. The President holds a high constitutional position and is the head of state.

Option 2: The Speaker of the Lok Sabha - This option is incorrect. The Speaker of the Lok Sabha is responsible for the proceedings and functioning of the Lower House of Parliament in India. However, the audit reports are not submitted to the Speaker.

Option 3: The Prime Minister - This option is incorrect. The Prime Minister is the head of government in India. While the Prime Minister plays a significant role in decision-making, the audit reports are not required to be submitted to the Prime Minister.

Option 4: The Vice President - This option is incorrect. The Vice President of India holds the position of the second highest constitutional authority. However, the audit reports are not required to be submitted to the Vice President.

In conclusion, the correct authority to whom the audit reports of the Comptroller and Auditor General of India relating to the accounts of the Union should be submitted is the President of India.