Felicia knits scarves and sells them to her friends. the first week, she knits four scarves and sells three for $50 each. the next week she buys her yarn at a discount, so she knits six scarves and is able to sell five for $40 each. which number represents quantity demanded at $40?

two
three
five
eight

Base on the questions in your post, and on my further calculation according to the given in your question, I would say that the answers would be the following. 
#1 The number that represents quantity demanded at $40 is C. 5
#2 The best option among the following is in letter C. Move to fiat currency.

I hope you are satisfied with my answer and feel free to ask for more if you have question and further clarification