Ok first of you need to know what a lipid is. A lipid is a class of organic compounds that are fatty acids or their derivatives and are insoluble in water but soluble in organic solvents. This includes waxes, steroids etc. Lipids are important for living cells. Together with carbohydrates and proteins, lipids are the main constituents of plant and animal cells. Cholesterol and triglycerides are also considered lipids.
So I would go with C.
Hope I helped. :)
