Which is a correct observation of soil after rain?

Correct answer: The soil is wet and dark brown

An observation is a statement based directly on what can be seen, touched, measured, or otherwise noticed at the time. It should describe evidence rather than express a personal judgement, a broad opinion, or a prediction about the future. Careful observations use simple, testable features such as colour, texture, wetness, smell, or temperature.

After rain, soil can be directly seen to contain moisture and often appear darker than dry soil. Thus “the soil is wet and dark brown” reports observable properties and is the suitable scientific observation. “Very good” is a judgement, “will always remain fertile” is a prediction, and “the best weather” is a preference. Therefore option B is correct.