a. How does each parameter of Vasicek model drt=(rt)+dWtQ influence the probability of generating negative short rates by forecasting under Q-measure over the next 30 years? Discuss. How about r0 - what impact does the starting point of your short rate forecast have on the above probability? b. BRIEFLY (one or two sentences each) discuss two valid criticisms of the Vasicek model. For each criticism you write, BRIEFLY (one sentence) argue whether the Hull-White model is capable or incapable of resolving your criticism