Which of the following is least likely to be important in holding the components of a biological membrane together?
a. hydrophobic interactions among the fatty acid tails of phospholipids on the same side of the membrane
b. hydrophobic interactions between the phospholipid tails and the surface of integral membrane proteins buried in the membrane
c. polar interactions among the phospholipid head groups on the same surface of the membrane
d. hydrophobic interactions among the fatty acid tails of phospholipids on opposite sides of the membrane
e. covalent interactions between the phospholipid and protein components of the membrane