C. It has been said that there are other ways to solve the problem.
This is because it shows that the author has investigated other possible solutions and not just the one that they are writing about. All of the other answers just support the claim without mentioning anything else.
Circumstances that may cause you to lose sleep is the mental health issue: Insomnia; You could be a physically healthy person but mentally not so much and it can seriously cut back on the amount of sleep you get. Factors that can cause you to lose sleep are: An uncomfortable bed, stress and anxiety, overthinking, not enough production throughout the day, light and sound.
Hope this helped :)
Answer:
we sold a ton of cookies at the bake sale but we still didn't have enough money to give to the charity
