What does Mill regard as the strong argument against public interference with individual liberty? ...

What does Mill regard as the strong argument against public interference with
  individual liberty?

a. It is wrong anytime, anywhere for anyone to interfere with the liberty of
  another.
  b. Let each by guided by his own conscience, in thought and deed, for each will
  have to answer for his own actions and inactions.
  c. When the public interferes, the odds are that it interferes wrongly and in the
  wrong place.
  d. The public need not interfere because the individual will always choose the
  course of action that he deems most worthy.