Answer:
Electromagnet A, which uses a piece of iron as its metal core will produce the stronger magnetic field
This is because of the ferromagnetic properties of iron
Silver is not attracted to magnets
Step-by-step explanation:
An electromagnet with an iron core produces a stronger magnetic effect, because ferromagnetic materials have the effect of concentrating the magnetic flux.
An electromagnet with a gold, silver or titanium core would be perfectly functional, as would one with a core made out of wood, or a human finger, that is to say they don't produce magnetic effects. Silver isn't noticeably magnetic. In fact, only iron, nickel, cobalt, gadolinium, neodymium and samarium are magnetic in our everyday lives. An ingot of pure silver isn't attracted to a magnet.