According to Wien's displacement law:

• A

  ${\mathrm{\lambda }}_{\mathrm{m}}=\mathrm{constant}$

• B

  ${\mathrm{\lambda }}_{\mathrm{m}}\mathrm{T}=\mathrm{constant}$

• C

  ${\mathrm{\lambda }}_{\mathrm{m}}{\mathrm{T}}^2=\mathrm{constant}$

• D

  ${{\mathrm{\lambda }}_{\mathrm{m}}}^2\mathrm{T}=\mathrm{constant}$