The presence of cholesterol in the plasma membranes of some animals

(a) enables the membrane to stay fluid more easily when cell temperature drops.
(b) enables the animal to add hydrogen atoms to unsaturated phospholipids.
(c) enables the animal to remove hydrogen atoms from saturated phospholipids.
(d) makes the animal more susceptible to circulatory disorders.
(e) makes the membrane less flexible, allowing it to sustain greater pressure from within the cell