Even if I knew nothing about electromagnetic waves I'd look for one of these items that I do understand at least a little and try to put it on the "is electromagnetic wave" or "is not electromagnetic wave." This is a good strategy for multiple choice questions. Another strategy is to look for two things that are a lot alike and then you can put both of them on the "is not the single item" list - in this case, "is not electromagnetic wave."
Our eardrums and other parts of our inner ear convert vibrations of the air into nerve impulses that we interpret as sound. Clap your hands and you are sending shockwaves through the air and these waves strike your eardrums and cause this who "hearing" process to happen. Education.com has an interesting activity that shows the mechanical action of sound waves, link is below. The "Tin can telephone" activity demonstrates this, too. Second link below.
Microwaves and radio waves are nearly the same, just different frequencies - in fact, there is a huge amount of data transmission on Earth using microwaves and has been for decades. X-rays are of the same ilk, but far higher in frequency. "Light" is another common item that is of the same nature. None of these vibrate the air, since they all pass through the vacuum of space. Therefore they must be different.
Electromagnetic waves are produced by fluctuating electric and magnetic fields. It can be accomplished by oscillating charges. Microwave, radio waves, and X-rays are some of the examples of electromagnetic radiation. Sound waves, on the other hand, are not part of electromagnetic wave spectrum; they are longitudinal compression waves. So, the answer to your question is B.