The 3rd & 4th statements regarding the fundamental Duties contained in the Constitution of India are correct.
According to the constitution of India, only Fundamental Rights can be enforced in the court of law.
DPSPs and Fundamental Duties are not enforceable in the court of law. Hence, statement 1 is incorrect.
The fundamental duties are defined as the moral obligations of all citizens to help promote a spirit of patriotism and uphold the unity of India.
Fundamental duties have not added in the constitution since its inception. Hence statement 2 is incorrect.
The fundamental duties of citizens were added to the constitution by the 42nd amendment act in 1976, upon the recommendations of the Swaran Singh Committee. Hence, statement 3 is correct.
The fundamental duties are contained in article 51(A) of Part 4(A) of the constitution which are, however, non-justifiable in character which means that no citizen can be punished by a court for violation of a fundamental duty.
​Fundamental duties are applicable only to the citizens of India. Hence, statement 4 is correct.