According to Article 51A of the Indian Constitution, which of the following Fundamental Duties requires citizens to uphold and protect the sovereignty, unity and integrity of India?

Correct option is C

The Third Fundamental Duty under Article 51A(c) states that every citizen shall "uphold and protect the sovereignty, unity and integrity of India." This reflects the moral responsibility of every Indian to safeguard national unity and pride.
Explanation of options: (a) ✘ The Second Duty deals with cherishing noble ideals from the freedom struggle. (b) ✘ The Fourth Duty is about defending the country and rendering national service. (c) ✔ The Third Duty specifically mentions protecting sovereignty, unity, and integrity. (d) ✘ The Seventh Duty is about preserving the natural environment.