Answer:
A) 
Explanation:
Maximum voltage =
Maximum voltage and rms voltage are related to each other by

The correct answer in this case is B. Harmonic.
The remaining answers refer to other parts of a musical composition, and some such as the pitch can even be found in the study of human voice.
A) the universe is expanding
Every galaxy is moving away from each other - not just us. And the further they are away, the faster they are moving
These are more of ideas to help your brain invent something less chessy...
Erosion is like corrosion, with no acid.
Erosion happens 'cuz the surface get frozen and beaten by the ocean. (they kinda rhyme) :)
Erosion is the transportation of, the deportation...
~OR~
I cant think of anything for weathering but i got something good, but its still cheesy/ ):
Erosions' got the grooves and so it moves. But weathering breakdown and changes so its molecules changes.
I'm sorry these kinda suck...