We consider the radiation emitted by the human body. Which of the following statements is true?

Wien's displacement law expresses the relation between:

$A$ black body has a maximum wavelength $\lambda_{m}$ at a temperature of $2000 \ K$. Its corresponding wavelength at a temperature of $3000 \ K$ will be:

Two bodies $A$ and $B$ of equal surface area have thermal emissivities of $0.01$ and $0.81$ respectively. The two bodies are radiating energy at the same rate. Maximum energy is radiated from the two bodies $A$ and $B$ at wavelengths $\lambda_A$ and $\lambda_B$ respectively. The difference in these two wavelengths is $1 \mu m$. If the temperature of body $A$ is $5802 \ K$, then the value of $\lambda_B$ is:

On investigation of light from three different stars $A, B$ and $C$, it was found that in the spectrum of $A$ the intensity of red colour is maximum, in $B$ the intensity of blue colour is maximum and in $C$ the intensity of yellow colour is maximum. From these observations, it can be concluded that

What are the values of Wien's constant in $SI$ and $CGS$ units?