The correct options are
A Defend the motherland when called upon.
B Uphold and protect the sovereignty, unity and integrity of India.
C Respect our Constitution.
It is our duty to respect our Constitution, our national flag and our national anthem. It is our duty to uphold and protect the sovereignty, unity and integrity of India. It is also our duty to defend the motherland when called upon to do so. These are the fundamental duties of the citizens of India and are enshrined in Part IV of the Indian Constitution.