The correct options are
A Passing a bill with at least two-thirds majority in both the houses of the Parliament
C Ratification by at-least half of the total states
The Parliament alone cannot change the power sharing arrangement. Even if the political leaders want to change the existing arrangement, it has to be first passed with at least two-thirds majority by both the houses of the Parliament. Also, this has to be ratified by at-least half of the total states. Only then the proposed changes will be implemented in the arrangement.