When Biological Membranes Are Frozen and Then Fractured,they Tend to Break

When biological membranes are frozen and then fractured,they tend to break along the middle of the bilayer.The best explanation for this is that

A) the integral membrane proteins are not strong enough to hold the bilayer together.
B) water that is present in the middle of the bilayer freezes and is easily fractured.
C) the hydrophobic interactions between ends of the fatty acid tails of the two phospholipid monolayers are the weakest interactions in the membrane.
D) the carbon-carbon bonds of the phospholipid tails are easily broken.