The conclusion is in the last sentence “…the more systematic and organised…produce more valid explanations…to support decisions”.
A – Wrong
The text does not discard common sense explanations and does not say that no decisions should be made based on common sense explanations.
B – Wrong
The text does not specifically suggest that Human nature has always preferred informal observation to scientific study. It only says that people have always been curious to explain the things happening around us.
C – Wrong
It is not suggested that scientists discount all common sense explanations. It only suggests that observations carried out by scientist is often more valid than common sense explanations.
D – Correct
This statement neither totally discounts common sense explanations nor does it say that common sense explanations are better than scientific ones. Hence, this is correct.
E – Wrong
The text does not suggest that scientific explanations support common sense explanations.