Assertion: For higher temperatures the peak emission wavelength of a black body shifts to lower wavelengths.Reason: Peak emission wavelengths of a blackbody is proportional to the fourth-power of temperature.

According to Wien's Displacement Law, ${\lambda }_{m}T=\text{constant}$. This means ${\lambda }_m\propto 1/T$, so as temperature increases, the peak wavelength shifts to lower values. The reason incorrectly states it is proportional to the fourth power (which describes total intensity via Stefan-Boltzmann law, not wavelength). Assertion is true, Reason is false.