Final answer:
Given that gravitational mass and inertial mass are equivalent, an object with a gravitational mass of 45.0 g also has an inertial mass of 45.0 g. The correct answer is option 4.
Step-by-step explanation:
The question pertains to the concept of gravitational and inertial mass, which are fundamental ideas in Physics. According to the equivalence principle, the gravitational mass (which determines the strength of an object's interaction with a gravitational field) is identical to its inertial mass (which determines how much an object resists acceleration when a force is applied to it). Therefore, when an object has a gravitational mass of 45.0 g, its inertial mass is also 45.0 g. This fact is grounded in Newton's second law of motion and the universal law of gravitation which provide the basis for understanding that mass is a measure of an object's inertia and is the same whether it's being considered in the context of gravity or motion.