All the options are incorrect , and it seems like Option D is misprinted that is instead of 2n-1, they have printed 2n - 1.
The correct answer should be 2n-1, because since the restriction has been removed (that is we can place big disk over small disk) the number of disk movement will be reduced.
No of Disk No. of movements
3 7(with restriction) i.e 2n - 1
5 (without restriction) i.e 2n-1
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4 15(with restriction)
7(without restriction)
Update: Options have now been corrected.