What is intensity? A.
The fastest your heart can beat
B.
How hard your body is working
C.
A place on your body where you can feel your heart beating
D.
None of the above

D

Explanation:

None of the above because the intensity is amount of a property, force, brightness, and magnetic field.

D. None of the above

Explanation:

D. None of the above, because the quality or condition of being intense. great energy, strength, concentration, vehemence, etc., as of activity, thought, or feeling: He went at the job with great intensity. a high or extreme degree, as of cold or heat. the degree or extent to which something is intense.

<>Hope this helps! : )

diagram is missing, but i will try to explain your doubt.

answer:

amplitude is the maximum displacement or distance moved on a point of a vibrating body or wave measured from its equilibrium position.it is equal to half the length of vibration path.

nah.   i'm just sleepy.