Please explain how this answer was obtained and how to draw this diagram? I am struggling to understand it, please explain it step by step, thanks !

* Why is the rm's demand curve atter than the total market demand curve in monopolistic competition? Suppose a monopolistically competitive firm is making a profit in the short run. What will happen to its demand curve in the long run? ANSWER: The atness or steepness of the firm's demand curve is a function of the elasticity of demand for the firm '5 product; The elasticity of the firm's demand curve is greater than the elasticity of market demand because it is easier for consumers to switch to another firm's highly substitutable product than to switch consumption to an entirely different product. Profit in the short run induces other firms to enter. As new firms enter, the incumbent firm's demand and marginal revenue curves shift to the left, reducing the profit- maximizing quantity. In the long run profits fall to zero, leaving no incentive for more firms to enter. Long-run