I think the correct answer would be the first option. Scientists need scientific models because they can often be used to make predictions. Models are representation of a process, natural phenomenon, or an idea that is being used to describe and define the occurrence which cannot be seen directly. These are very useful tools in order to predict certain values that would be tedious to be obtain through experiment. Also, this would help scientists to obtain values that is outside the range of their experiment. Examples of these models are the models of the motions of the earth, sun and the moon.