To most people in Hong Kong, fast food is regarded as junk food. The following news relate to the fast food market in Hong Kong have been reported recently.

Source A: A recent government report has shown the average monthly salary of Hong Kong people increases from HK$18,000 to HK$20,000.

Source B: Many fast food restaurants closed down in Hong Kong this year.

(a)Consider the information of source A only, use a demand and supply analysis to explain the effects on the equilibrium price and equilibrium quantity of the fast food market in Hong Kong. No demand-and-supply diagram is needed but you need to describe how the curve(s) shifts in your written explanation.

(b)Consider the information of source B only, use a demand and supply analysis to explain the effects on the equilibrium price and equilibrium quantity of the fast food market in Hong Kong. No demand-and-supply diagram is needed but you need to describe how the curve(s) shifts in your written explanation.

(c)To consider both the effects in part (a) and (b) above, what are the combined effects on the equilibrium price and equilibrium quantity of the fast food market in Hong Kong? Why does the fast food market in Hong Kong have the observation of decreased price based on the two pieces of information? Illustrate with a demand and supply diagram.