Explanation:

- The term "Republic" in the Indian Constitution signifies that the head of the state is an elected or appointed leader, not a monarch.

- Option 1: Elected head

- ? The President of India is an elected head.

- The President is chosen by an electoral college.

- This aligns with the principle of being a Republic.

- Option 2: Nominated head

- Refers to leaders chosen through appointment, not popular vote.

- This doesn't apply to the concept of a Republic for India.

- Option 3: Subordinate head

- Implies a leader with limited power, secondary to another.

- Not relevant to the term "Republic."

- Option 4: Hereditary head

- Leadership passed down through family lineage.

- Contradicts the concept of a Republic.