Given that A , B and C are the vertices of a triangle and that ∠ C B A = 80 ∘ and ∠ A C B = 35 ∘ , label the triangle with the correct vertices, A , B , or C . Select the correct answer from the options below.

Last month, a 770 g box of cereal was sold at a grocery store for $3.10. however, this month, the cereal manufacturer launched the same cereal in a 640 g box, which is being sold at $2.50. what is the percent change in the unit price?