Explanation:

• Both the options a and b are correct. 
• The Supreme Court of India in the famous Gopalan Case (1950) held that protection under Article 21 is available only against arbitrary executive action and not against arbitrary legislative action. It clarified that if personal liberty of an individual is taken away by a law, the validity of the law cannot be questioned. In the same case the Supreme Court held personal liberty would only mean liberty relating to the person or body of the individual.
• However, in the Maneka Gandhi Case (1973) the Supreme Court overruled its judgement in the Gopalan Case by widely interpreting Article 21. It stated that protection under Article 21 should be available not only against arbitrary executive action but also against arbitrary legislative action by introducing the American concept of ‘due process of law’. It pronounced the expression ‘Personal Liberty’ in Article 21 is of the widest amplitude and it covers a wide range of rights that go to constitute the personal liberties of a man.