**Explanation:**

The concept of fundamental duties was not borrowed from Russia, but rather from the former Soviet Union. The correct answer is option 'A'. Here is a detailed explanation:

**Fundamental Duties:**
Fundamental duties are a set of moral obligations and responsibilities that citizens of a country are expected to follow. They are intended to promote a sense of discipline, integrity, and commitment towards the nation and society. These duties are not enforceable by law but are considered essential for the overall well-being of the country.

**Origin of Fundamental Duties:**
The concept of fundamental duties was first introduced in the Indian Constitution in 1976 through the 42nd Amendment. It was inspired by the Constitution of the former Soviet Union, which had a similar provision for fundamental duties.

**The Soviet Union Connection:**
The Soviet Union, officially known as the Union of Soviet Socialist Republics (USSR), was a socialist state that existed from 1922 to 1991. The Soviet Constitution, adopted in 1936, included a chapter on fundamental rights and duties of citizens.

**Influence on Indian Constitution:**
The framers of the Indian Constitution were influenced by the socialist ideas and principles of the Soviet Union. They believed that citizens should not only have rights but also certain responsibilities towards the nation. As a result, they incorporated the concept of fundamental duties in the Indian Constitution.

**42nd Amendment:**
The 42nd Amendment to the Indian Constitution, enacted in 1976, introduced a new part titled 'Fundamental Duties'. It added Article 51A, which outlined ten fundamental duties that citizens should fulfill towards the nation and society. These duties include respecting the Constitution, promoting harmony, safeguarding public property, etc.

**Conclusion:**
In conclusion, the concept of fundamental duties in the Indian Constitution was borrowed from the former Soviet Union. The framers of the Indian Constitution were influenced by the socialist ideas and principles of the Soviet Union and believed in the importance of citizens' responsibilities towards the nation. Thus, the correct answer is option 'A' - Russia.