Option 1: To provide friendly cooperation to the people of the neighbouring countries. This option is not a fundamental duty of citizens under the Constitution of India. While it is encouraged to have friendly relations with neighbouring countries, it is not a mandated duty for citizens.

Option 2: To protect monuments of national importance. This option is not a fundamental duty of citizens under the Constitution of India. While it is essential to protect and preserve monuments of national importance, it is primarily the responsibility of the government and relevant authorities.

Option 3: To defend the country and render national service when called upon to do so. This is the correct option. According to Article 51A (d) of the Indian Constitution, it is a fundamental duty of citizens to defend the country and render national service when required. This duty includes serving in the armed forces or any other capacity deemed necessary for the security and well-being of the nation.

Option 4: To know more and more about the history of India. This option is not a fundamental duty of citizens under the Constitution of India. While it is encouraged to have knowledge about the history of India, it is a personal choice and not a mandated duty.

Therefore, the correct answer is option 3.