**Explanation:**

Article 340 of the Constitution of India empowers the President of India to appoint a Commission to investigate the conditions of socially and educationally backward classes. The correct answer is option 'D' - Backward Classes.

**Appointment of the Commission:**
1. The President of India has the authority to appoint a Commission to investigate the conditions of socially and educationally backward classes.
2. The Commission is tasked with making recommendations for the improvement of these classes.

**Objective of the Commission:**
The main objective of the Commission appointed under Article 340 is to study and investigate the conditions of socially and educationally backward classes in India. The Commission aims to identify the issues faced by these classes and make recommendations for their improvement.

**Scope of Investigation:**
The Commission's investigation covers various aspects related to the conditions of socially and educationally backward classes, including:
1. Social and educational backwardness
2. Inadequate representation in government jobs and educational institutions
3. Discrimination and disadvantage faced by these classes
4. Measures to uplift and improve the conditions of these classes

**Recommendations:**
Based on its investigation, the Commission is expected to provide recommendations to address the issues faced by socially and educationally backward classes. These recommendations may include:
1. Reservation policies in government jobs and educational institutions
2. Affirmative action programs to promote the welfare and development of these classes
3. Measures to eliminate discrimination and ensure equal opportunities for these classes
4. Steps to enhance the social, economic, and educational status of these classes

**Implementation of Recommendations:**
The recommendations made by the Commission are crucial for the government to formulate policies and programs for the upliftment of socially and educationally backward classes. It is the responsibility of the government to implement these recommendations effectively and ensure the betterment of these classes.

In conclusion, Article 340 of the Constitution of India provides for the appointment of a Commission to investigate the conditions of socially and educationally backward classes. The Commission's objective is to study, identify issues, and make recommendations for the improvement of these classes.