The correct answer is (d). Articles 20 and 21 cannot be suspended during the national emergency.
Article 20 guarantees protection in respect of conviction for offences. It states that no person shall be convicted of any offence except for violation of a law in force at the time of the commission of the act charged as an offence, nor be subjected to a penalty greater than that which might have been inflicted under the law in force at the time of the commission of the offence.
Article 21 guarantees protection of life and personal liberty. It states that no person shall be deprived of his life or personal liberty except according to procedure established by law.
These two articles are fundamental rights and cannot be suspended even during a national emergency.