In which of the following cases, the Supreme Court adhered to the ‘doctrine of the basic structure’ and clarified that it would apply to constitutional amendments enacted after April 24, 1973 (i.e. the date of the judgement of Kesavananda Bharati case) ?
1) Menaka Gandhi case (1978)
2) Minerva mills case (1980)
3) Waman Rao Case (1981)
4) S. R. Bommai case (1994)
3) Waman Rao Case (1981)