The inertia of an object is its resistance to change motion, i.e. to accelerate. Then, the inertia is related to the mass. You can say that mass is the inertia of the object. So, if the two boxes are identical, undoubtely the box with books will have more mass, or more inertia, than the box with cotton balls. Therefore, the answer is A bos of books has more inertia than a box of cotton balls.
