12.491 Answer the following questions and provide a brief explanation or illustration: a. Is it possible for X in Equation (2.1) to be empty but D in Equation (2.2) to be nonempty? b. Is there a relationship between redundancy and degeneracy of a polyhedral set? C. Does degeneracy imply redundancy in two dimensions? d. If the intersection of a finite number of half-spaces is nonempty, then this set has at least one extreme point. True or false? Explain. e. An unbounded #-dimensional polyhedral set can have at most / extreme directions. True or false? Explain. f. What is the maximum (actual) dimension of ) = {x ; Ax = b, x 2 0). where A is m * n of rank r, with r