En el mundo la mayor parte de la energia proviene de

object 2 because all the other ones are wrong

there are no contact forces mentioned on the list of choices that you've provided.

answer///scientific method;

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.