Let W be the union of the second and fourth quadrants in the​ xy-plane. That​ is, let W= x y : xy≤0. Complete parts a and b below. a. If u is in W and c is any​ scalar, is cu in​ W? Why? A. If u= x y is in​ W, then the vector cu=c x y = cx cy is in W because (cx)(cy)=c2(xy)≤0 since xy≤0. B. If u= x y is in​ W, then the vector cu=c x y = cx cy is not in W because cxy≥0 in some cases. C. If u= x y is in​ W, then the vector cu=c x y = cx cy is in W because cxy≤0 since xy≤0.