Cholesterol belongs to the groups of lipids called

cholestrol is part of sterols / steroids which is one of the 4 classes of lipids
cholestrol characterized with 4 fused carbon rings, like all sterols do
other sterols are sex-trait hormones like testosterone etc.

other lipid groups are fats (glycerol and fatty acids), phospholipids (phosphate head and faitty acid tails), and waxes (contain alcohol group)

The correct answer:   [c]:   "cell phone call" .