The correct answer is option 4: 1 and 4 only.

The principles of the Panchsheel, also known as the Five Principles of Peaceful Coexistence, are based on mutual cooperation and respect between nations.

1. Peaceful coexistence: This principle emphasizes the importance of maintaining peace and harmony between nations. It promotes the idea of resolving conflicts through peaceful means, such as dialogue and negotiation, rather than resorting to violence or aggression.

2. Mutual protection of the environment: This principle highlights the need for nations to work together to protect the environment and promote sustainable development. It emphasizes the importance of preserving natural resources and ensuring their sustainable use for the benefit of present and future generations.

3. Mutual protection of indigenous population: This principle is not one of the original principles of the Panchsheel. Therefore, option 1, 2 and 3 is incorrect.

4. Mutual non-aggression: This principle stresses the importance of refraining from any form of aggression or use of force. It promotes the idea of peaceful coexistence and encourages nations to resolve their differences through peaceful means, such as diplomacy and negotiation.

In conclusion, the correct principles of the Panchsheel are peaceful coexistence (option 1)