What produces a magnetic field? a. electrical resistance b. increase in ohms c. transfer of protons d. movement of electrons

in this image, you can see solar radiation going through ocean water.

no image, but probably absorption

adding a(n) to an electric circuit would increase the magnetic field around a wire;

b. solenoid

a solenoid is a type of electromagnet whose purpose is to generate a controlled magnetic field.

if the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet.