The correct answer is (b). Granville Austin is a Canadian political scientist who specializes in Indian politics and law. He is the author of several books on India, including The Indian Constitution: Cornerstone of a Nation (1966), which is considered a classic work on the subject.
(a) John Austin was an English jurist who is considered the father of legal positivism. He is best known for his work on the nature of law and sovereignty.
(c) A.L. Goodhart was an English jurist and legal philosopher. He is best known for his work on the philosophy of law and the rule of law.
(d) H.L.A. Hart was an English jurist and legal philosopher. He is best known for his work on the philosophy of law, including his book The Concept of Law (1961).