Sphingolipids
I. contain a glycerol core with a phosphocholine headgroup.
II. contain a modified sphingosine.
III. often function as receptor components of membranes.
IV. function as a precursor to sterols.
A) I, II, IV
B) II, IV
C) I, II, III
D) II, III
E) II, III, IV
Answer: D) II, III