The correct answer is option 'A', which is Article 338.

The establishment of the National Commission for Scheduled Castes is envisaged in Article 338 of the Indian Constitution. This article provides for the appointment of a commission to investigate and monitor all matters relating to the safeguards provided for the Scheduled Castes (SC) under the Constitution.

Here is a detailed explanation of Article 338 and the role of the National Commission for Scheduled Castes:

1. Article 338: Article 338 of the Indian Constitution deals with the National Commission for Scheduled Castes. It states that there shall be a commission known as the National Commission for Scheduled Castes, which will consist of a Chairperson, Vice-Chairperson, and other members appointed by the President of India.

2. Function of the Commission: The primary function of the National Commission for Scheduled Castes is to investigate and monitor all matters relating to the safeguards provided for the Scheduled Castes under the Constitution. It is responsible for the protection of their rights, welfare, and development.

3. Safeguards for Scheduled Castes: The Constitution of India provides various safeguards for the Scheduled Castes to ensure their social, educational, and economic development. The National Commission for Scheduled Castes plays a crucial role in ensuring the effective implementation of these safeguards.

4. Powers of the Commission: The Commission has the power to inquire into specific complaints regarding the deprivation of rights and safeguards of the Scheduled Castes. It can also participate and advise on the planning process of socio-economic development of the Scheduled Castes and evaluate the progress made in their implementation.

5. Reports and Recommendations: The Commission is required to submit annual or special reports to the President on the measures taken for the welfare of the Scheduled Castes. It can also make recommendations to the President for the effective implementation of the safeguards and for any other matter that it considers necessary.

6. Role in Legal Matters: The National Commission for Scheduled Castes can also intervene in any proceeding involving any issue concerning the Scheduled Castes before a court. It can exercise its powers of investigation and inquiry to ensure the protection of the rights of the Scheduled Castes.

7. Independence and Autonomy: The Commission is an independent body and is not under the control of any government department. This autonomy enables it to function impartially and effectively in safeguarding the rights of the Scheduled Castes.

In conclusion, Article 338 of the Indian Constitution envisages the establishment of the National Commission for Scheduled Castes. This commission plays a vital role in investigating and monitoring matters related to the safeguards provided for the Scheduled Castes and ensuring their welfare, development, and protection of their rights.