Please help explain and answer, this is a practice question for my class, please explain. only complete C) a and b are for reference

a) hot dogs is currently in equilibrium

b) the cost of beef (a major ingredients of hot dogs) decreases. What will happen to the market for hot dogs?

c) In a graph, represent what happened in part b) in the markets for hot dogs and pizzas. Then, use the graph to argue whether the consumers of hot dogs are better or worse off after the change. Do the same for the suppliers of pizzas