Explanation:

- Option 1: Articles 14 to 18

- These articles deal with the right to equality. During a national emergency, these rights can be suspended.

- Option 2: Article 19

- This article provides for the protection of certain rights regarding freedom of speech, etc. It can be suspended during a national emergency.

- Option 3: Article 20, 21

- These are the fundamental rights concerning protection in respect of conviction for offenses and protection of life and personal liberty. These cannot be suspended, even during a national emergency.

- Option 4: Article 29, 30

- These articles relate to cultural and educational rights, which can be affected during a national emergency.