c. Graded beds are evidence of a decrease in current velocity during deposition whereby coarse sediments settle out first, followed by finer sediments as the velocity decreases over time.
The radiation fog is formed when the land surface cools after the sunset in the conditions of the clear sky. Thus the cooling ground cools the air above it and as a result of this the conduction causes the air temperature to fall and hence it reaches the dew point and forms a fog.
