Under which of the following Amendments were the privy purses of erstwhile rulers of princely states abolished?

'Privy purse' refers to payments made by the Indian Government to the rulers of erstwhile princely states as a part of their agreement merge with the Indian state, whereby they lost all their ruling rights. The 26^th Amendment, enacted in 1971, amended article 366 of the Indian Constitution, leading to the abolition of privy purses of erstwhile royal families. The 27^th Amendment Act (1972) led to the reorganization of Mizoram into a Union Territory with a legislature and council of ministers. The 28^th Amendment Act (1972) rationalized civil service rules to bring in uniformity among the appointments made prior to and post independence. The 29^th Amendment Act (1972) amended Schedule 9 of the Indian Constitution and placed land reform acts and amendments to this act under Schedule 9.