Question

A scientist wants to use a model to help present the results of his detailed scientific investigation.

Why would a model be useful?
because the model makes the concepts easier to understand
because the model is easy to put together and to use
because the model prevents other scientists from asking questions
because the model requires the audience to pay full attention to it

Answer 1

Because the model makes the concepts easier to understand.

The other choices are incorrect: models don't necessarily have to be easy to build, they don't prevent questions (good science invites scrutiny), and "requiring full attention" isn't a valid reason to use a model.