سوال ۱۲ کنکور ارشد مهندسی برق ۱۴۰۴

PASSAGE 1 (paragraph 1):

Electricity and magnetism were regarded as distinct phenomena for quite a while. However, as scientists started studying electrodynamics, they noticed that current-carrying wires could be affected by magnets, and also that magnetic fields could be generated by currents. Somehow electricity and magnetism were linked. Formally, electromagnetism is the field of physics that looks at how magnetic fields can affect moving electric charges and how changing magnetic fields can induce electric currents. It also looks at how magnetic fields can be generated by electric fields or electric currents. It (underlined) even explains the origin of electromagnetic radiation. Ultimately, electromagnetism describes electricity and magnetism within one single framework as two manifestations of the same fundamental electromagnetic force.

12- The underlined word "it" in paragraph 1 refers to «..........» .