The correct answer is option 'B', Comptroller and Auditor General. The Comptroller and Auditor General (CAG) is known as the 'friend, philosopher and guide' of the members of Parliament. Let us understand why this is the correct answer.

Explanation:

Role of the Comptroller and Auditor General (CAG):
1. The CAG is the constitutional authority responsible for auditing the accounts of the government of India, both at the central and state levels.
2. The CAG ensures transparency and accountability in the financial operations of the government.
3. The CAG plays a crucial role in ensuring that public funds are utilized efficiently and effectively.
4. The CAG reports its findings to the President or Governor, who then places these reports before the Parliament or State Legislature.
5. The CAG acts as a watchdog to ensure that government departments and agencies comply with financial rules and regulations.

Importance for Members of Parliament:
1. The CAG's reports provide valuable insights into the financial management of the government.
2. Members of Parliament rely on these reports to scrutinize the government's financial decisions and policies.
3. The CAG's reports help in identifying instances of financial mismanagement, irregularities, or corruption within the government.
4. Members of Parliament can use the CAG's findings to hold the government accountable and demand corrective actions.
5. The CAG's recommendations and observations are often considered during parliamentary debates and discussions on various issues.
6. Members of Parliament can seek guidance from the CAG on matters related to financial management and auditing.

Conclusion:
Given the role and importance of the Comptroller and Auditor General in auditing the government's accounts and ensuring financial transparency, it is evident why the CAG is considered the 'friend, philosopher and guide' of the members of Parliament. The CAG's reports and recommendations serve as a valuable resource for MPs in their legislative and oversight functions.