Which of the following statements about Fischer projections is false?

W) The structure may be rotated by 90 degrees or 180 degrees

X) Four bonds to a chiral [KY-ruhl] carbon make a cross with the carbon at the intersection of horizontal and vertical lines

Y) Two horizontal bonds are directed toward the viewer

Z) Two vertical bonds are directed behind the stereogenic carbon
W) THE STRUCTURE MAY BE ROTATED BY 90 DEGREES OR 180 DEGREES