Layla is baking brownies (b), cupcakes (k), and peanut brittle (p) for a gift basket she is creating for an auction. She plans to include six brownies, five cupcakes, and twelve pieces of peanut brittle. The total cost she spent to bake the goods is represented by C. C=6b+5k+12p

Which of the following is an equivalent expression that reveals how much it cost to bake one cupcake?

k=C−18bp5

k=C+6b+12p5

k=C5−6b−12p

k=C−6b−12p5