(a) We are trying to learn regression parameters for a dataset which we know was gen- erated from a polynomial of a certain degree, but we do not know what this degree is. Assume the data was actually generated from a polynomial of degree 5 with some added noise, that is y = wo+w₁x + w₂x² + W3x³ + w₁x¹ + W5x5 + €₂ E~ N(0, 1). For training we have 100 (x, y)-pairs and for testing we are using an additional set of 100 (x, y)-pairs. Since we do not know the degree of the polynomial we learn two models from the data. Model A learns parameters for a polynomial of degree 4 and Model B learns parameters for a polynomial of degree 6. Which of these two models is likely to fit the test data better? Justify your answer. (4 marks)
