Water potential of atmosphere in a humid weather is about:

Correct option is B

Water potential is a measure of the potential energy of water in a system compared to pure water, and it's expressed in megapascals (MPa).
In the context of the atmosphere, water potential becomes highly negative due to the vapor state and the low water content in the air, especially in dry conditions.
Even in humid weather, the atmosphere exerts a very strong pull on water due to its low relative humidity compared to liquid water, resulting in a highly negative water potential.
In humid weather, water potential of the atmosphere is typically around –10 MPa.
In dry air, it can drop as low as –100 MPa or more negative.
Option:
(a) –100 MPa: Too low for humid weather; typical of very dry air.
(b) –10 MPa: ✅ Correct. This is a common value in humid atmospheric conditions.
(c) –1 MPa: Not negative enough for atmospheric vapor pressure levels.
(d) –0.1 MPa: Too close to water potential of moist soils, not the atmosphere.