Which of the following are not polymeric?

Which of the following acts as a precursor for steroid hormones?

In the structure of a triglyceride,the glycerol molecule is linked to fatty acid molecules by which bond?

Which vitamin is synthesized from lipid derivatives?

Consider the following four statements $(a-d)$ and select the option which includes all the correct ones only $:-$
$(a)$ Lipids are generally water insoluble.
$(b)$ The $R$ group could be a methyl $(-CH_3)$ or ethyl $(-C_2H_5)$ or higher number of $-CH_2$ groups ($1$ carbon to $19$ carbons) in fatty acids.
$(c)$ Palmitic acid has $16$ carbons including the carboxyl carbon.
$(d)$ Arachidonic acid has $21$ carbon atoms including the carboxyl carbon.

Which of the following statements is inconsistent with saturated fatty acids?