Out of the four options presented in this problem, the most probable answer would be A. humidity.
Weather has many characteristics which includes, but are not limited, to air temperature, wind speed, the directions of the wind, cloud cover, the type of clouds present, amount of precipitation, the type of precipitation, and of course humidity. Although B. winds is an option, it isn't ultimately a main characteristic since some weathers doesn't involve winds too much. The humidity, however, is present in all kinds of weather. The other characteristics help in differentiating which weather to which weather.
Answer and Explanation:
This can be explained as in Rutherford's model of atom the electrons orbits the nucleus which means that they will travel around the nucleus with some velocity and hence radiate electromagnetic waves which results in the loss of energy due to which the electron keeps coming closer and eventually falls into the nucleus.
But Bohr came up with a better explanation as according to the Bohr's atomic model, electrons stay fixed in orbit with certain energy in different shells around the nucleus and can only jump from an energy level to another if that specific amount of energy is supplied to it.
This model is based on the quantization of energy thus giving an explanation why electrons do not fall into the nucleus of an atom.
It can solidify, it depends on the tempeture.