4. Extra credit: 20 points A. Why does ahouse broker usually recommend her clients the median house price in a community but not average price? [5 points) B. We have a linear model 3/ = a + b "' x + e, please specify the [median ) L1-regression for this model. [5 points} C. How do you measure Management Quality fora stock-selection strategy? [5 points] D. What is the major contribution of Stephen Ross to finance? (5 points]