Laws are essentially certain rules put in place by our government. You must comply with the law or you will face consequences. Some examples of laws are DUI, Murder, Theft, and the many, many Traffic Laws. Everyone knows that you can't drive under influence, you cannot commit murder, you cannot steal, and you must not violate any traffic laws.
I hope this is the answer you're looking for.
The answer is who because whom is not really saying what she is wondering
“Fair is foul and foul is fair” ...
“Brave Macbeth – Well he deserves that name – Confronted him with brandished steel” ...
“Stars hide your fires; let not light see my dark and deep desires” ...
“Come you spirits, that tend on mortal thoughts.
Answer: Solar energy is a convenient resource