Which of the following is not a type of simple lipid?

Match the lipids given in Column-$I$ with their occurrence in Column-$II$.

Column-$I$	Column-$II$
$i$. Cerebrosides	$a$. Most of the cells in animal body
$ii$. Waxes	$b$. Dioscorea
$iii$. Diosgenin	$c$. Myelin sheath
$iv$. Cholesterol	$d$. Sebaceous glands of the skin

Lipoproteins are an example of which type of lipids?

$A$ - Glycerol is tri-hydroxy propane and it is a simple lipid.
$R$ - All lipids are simple type.

Which of the following statements regarding lipids are correct?
$I$. Water soluble
$II$. Water insoluble
$III$. Some lipids contain phosphorus
$IV$. Found only in the cell membrane
Choose the correct options.

$A$: Linolenic acid is an essential fatty acid.
$R$: Linolenic acid cannot be synthesized in human beings.