Relative humidity is given by (where pv = Partial pressure of water vapour, pb = Barometric pressure, ps = Pressure of saturated air, pd = Pressure at dry bulb temperature, pw = Saturation pressure corresponding to wet bulb temperature and = Degree of saturation)

Answer: Option B

Relative humidity is given by $$\frac{\mu }{1-\left(1-\mu \right)\frac{{\text{p}}_{\text{s}}}{{\text{p}}_{\text{b}}}}$$
Where
p_v = Partial pressure of water vapour,
p_b = Barometric pressure,
p_s = Pressure of saturated air,
p_d = Pressure at dry bulb temperature,
p_w = Saturation pressure corresponding to wet bulb temperature,
$$\mu$$ = Degree of saturation