According to Wein’s Displacement Law:
The wavelength of the peak of the blackbody radiation is inversely proportion to the absolute temperature of the emitter.

Here, λ_m is the wavelength at maximum intensity, T is the absolute temperature in kelvins and b is the Wein constant.
Also,

Where c is speed of light and v is the frequency.
Now when the absolute temperature of the body is doubled,
T becomes 2T. Since LHS is equal to a constant, the RHS of the Wein’s displacement law must be doubled too.
This becomes,

Here v₀ is the frequency at maximum intensity. As we can see doubling absolute temperature doubles frequency too.
Hence option (a) is correct.
Now, According to Stefan’s Law, the rate of emission of radiated energy is proportional to the fourth power of absolute Temperature,


where u is the radiated energy. Thus, the total energy emitted will increase by a factor of 16.
Thus, options (a) and (c) are the correct options.