In an elastic collision, . A. an individual molecule in the collision never loses energy B. the molecules involved in the collision move in a circular motion C. the total energy of all molecules in the collision remains constant D. the molecules involved in the collision are held to each other by strong intermolecular interactions

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Im pretty sure its B im very sorry if its wrong.

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.