In Commercial Bank of Australia Ltd v Amadio (1983) 151 CLR 447: Select one: a. The High Court set out some situations of "special disadvantage" for undue influence but recognised that it would be impossible to define them definitively. b. The court exercised its equitable jurisdiction in to set aside a transaction as unconscionable where the one party was under a special disadvantage and the other had taken unconscionable advantage of them. c. The High Court clarified the principles of duress. d. It was held that a court will always grant relief wherever a contract operates harshly or oppressively against a party