Answer:
B. a model
Explanation:
A model is a representation of a process, event, molecule or situation that is too big or too small to be studied in its actual size. The models can be a physical or mental representation, the important thing is that they allow something to be visualized and touched whenever necessary so that a study can be completed.
As an example of models, we can mention: models of DNA molecules, model of volcanoes, model of atoms, model of how the information passes between neurons, building models, among others.
