Which of the following statements is NOT true?（）

A.Oliver Cromwell became Lord Protector of the Commonwealth of England in 1653 by the Petition of Right.
B.Oliver Cromwell crushed without mercy a rebellion in Ireland.
C.Oliver Cromwell suppressed the Levellers,a group within his own army who advocated total religious and social equality.
D.Oliver Cromwell replaced the Rump with an assembly largely chosen by himself.