Question

b. what is an advantage of using the 4.5 - 7.5 paper?

Explanation:

Without more context about what the 4.5 - 7.5 paper is (e.g. if it's pH - range paper, size - specified paper etc.), a general answer could be that it might be suitable for a specific range of tasks within its intended use. For example, if it's pH paper in that range, it can accurately measure slightly acidic to slightly basic solutions.

Answer:

There is not enough information provided to give a definite advantage. It depends on the context of what the 4.5 - 7.5 paper is used for.