A cylindrical bar

Looking carefully to the bar magnet we will observed symmetry about its axial axis in magnetic field of a bar magnet, so when magnet is rotated there is no change in magnetic field which means there is no charge i.e. change in flux is null hence no current i.e. then obviously ammeter will show zero deflection on it.

Now come to the options, with our above discussion we can definitely say that (a) option is wrong. If there is no current in ammeter which means, there is no meaning of time period or sinusoidal or non-sinusoidal current so option (c) & (d) also wrong.

Hence (b) option is correct answer.