Answer:
The correct option is D) The real molecule is too small to easily observe.
Step-by-step explanation:
A scientific model is a representation of scientific research or any system or phenomenon which occurs. A scientific model helps us easily understand the events occurring even in those systems which cannot be seen with the eye. Many phenomenons occurring in the nature are visualized through models as the human eye is unable to see them.
For example, the arrangement of atoms in a molecule cannot be seen by the human eye. Hence, models of atoms in a molecule help us easily understand the different bondings present to make up a molecule.