Ayanfe spends all her income on good X and good Y. As the price of good X increases while the price of the price of good Y remains fixed, Ayanfe's price-consumption curve is horizontal.

a) Let the price of good Y be $1 per unit and Ayanfe's income be M. Draw the diagram that illustrates the situation described above.

b) Is good X a complement or a substitute for good Y? Explain.

c) What is Ayanfe's price elasticity of demand for good X? Explain.