Which of the following is an example of an unsaturated fatty acid?

$A$ typical fat molecule is made up of

Match the following columns correctly:

Column-$I$	Column-$II$
$(a)$ Fat	$(i)$ All fatty acids are saturated and long-chained
$(b)$ Oil	$(ii)$ All fatty acids are unsaturated and short or long-chained
$(c)$ Wax	$(iii)$ Alcohol molecule is monohydroxy alcohol
$(d)$ Complex lipid	$(iv)$ Lipid plus non-lipid component

Each molecule of fat is composed of what?

Identify the saturated and unsaturated fatty acids from the following list:
$I-$ Acetic acid,$II-$ Methanoic acid
$III-$ Arachidonic acid,$IV-$ Palmitic acid
$V-$ Stearic acid,$VI-$ Oleic acid
Select the correct grouping for Saturated fatty acids and Unsaturated fatty acids.

Which substance produces more than twice the energy compared to carbohydrates?