Fundamental duties are the moral obligations that every citizen of India has towards their country. They are enshrined in the Indian Constitution under Part IV-A, Article 51A. These duties serve as a reminder to citizens to be responsible and proactive in contributing to the welfare of the nation.

The correct answer is option 'D' which states that all of the given options – safeguarding public property, protecting the sovereignty, integrity, and unity of India, and developing scientific temper and humanism – are fundamental duties.

1. Safeguarding Public Property:
- Safeguarding public property means taking care of and protecting the assets that belong to the public or the government.
- It includes preventing damage, destruction, or misuse of public property such as government buildings, parks, monuments, etc.
- This duty emphasizes the importance of being responsible citizens and ensuring the welfare of the community as a whole.

2. Protecting the Sovereignty, Integrity, and Unity of India:
- Sovereignty refers to the supreme power or authority of a nation to govern itself without interference from external forces.
- Integrity refers to the adherence to moral and ethical principles, honesty, and uprightness.
- Unity refers to the state of being united or joined as a whole.
- Protecting the sovereignty, integrity, and unity of India means being loyal and committed to the nation, respecting its diverse cultures and religions, and working towards maintaining harmony and unity among the citizens.
- It also involves defending the country against any threats to its independence and ensuring its territorial integrity.

3. Developing Scientific Temper and Humanism:
- Developing scientific temper means promoting a rational and logical approach towards understanding the world and solving problems.
- It encourages citizens to question superstitions, base their beliefs on evidence and reason, and develop a scientific mindset.
- Humanism refers to the belief in the value and dignity of every human being and the importance of compassion, empathy, and social responsibility.
- This duty emphasizes the need for citizens to be open-minded, progressive, and compassionate towards others, promoting equality, justice, and human rights.

In conclusion, all of the given options – safeguarding public property, protecting the sovereignty, integrity, and unity of India, and developing scientific temper and humanism – are fundamental duties that every citizen of India should fulfill. These duties aim to promote responsible citizenship, national unity, and the overall welfare of the nation.