Platelet-Activating Factor Is Much More Water Soluble Than Most Other

Platelet-activating factor is much more water soluble than most other glycerophospholipids due to which feature?

A) its ether-linked alkyl chain at the C-1 of glycerol
B) its ester-linked acetic acid at the C-2 of glycerol
C) its ethanolamine head group
D) its lack of any long alkyl chains linked to glycerol
E) the presence of sphingosine, rather than glycerol, as a lipid backbone