Hello,
I believe you're asking which option is true. If so, A) do not require a medium. Unlike mechanical waves, electromagnetic (or light) waves do not require a medium. It has been proven that light travels in a straight line. Light waves are, in fact, electromagnetic radiation, and they can travel in a vacuum.
Faith xoxo
Who is Dede and what are her symptoms. We need more context
The answer is B. It will increase blood pressure because the heart is contracting faster
