b) (1 point) There are 900 potential buyers for a mobile phone in a market. The poten- tial buyers are heterogenous in their valuation for mobile phones and each potential buyer consumes at most 1 mobile phone. In other words, no potential consumer sees any value for a second mobile phone. The word "heterogenous" means that the potential buyers are different from one another. The potential buyers differ in their willingness to pay for a phone. These willingness to pays are uniformly distributed between 1 and 900. Hence, someone has willingness to pay 900, someone has willingness to pay 899, someone has willingness to pay 898,..., someone has willingness to pay 2, and someone has willingness to pay 1 for a mobile phone. Please draw the market demand curve for mobile phones. (Again: Market demand curve shows for any given price how many units in total consumers in this economy would buy. Please draw price on the vertical axis and quantity on the horizontal axis.)