Platelet activating factor (PAF) has all of the characteristics EXCEPT:

A) PAF is a potential mediator in inflammation, allergic responses and shock.
B) PAF is a sphingolipid.
C) PAF has a beneficial effect on toxic-shock syndrome.
D) PAF is involved in implantation of the egg in the uterine wall.
E) PAF stimulates production of fetal lung surfactant.