Which of the following is the unsaturated fatty acids?

The typical formula for saturated monocarboxylic fatty acids is ${\mathrm{C}}_{\mathrm{n}}{\mathrm{H}}_{2\mathrm{n}}{\mathrm{O}}_2$
​The formula for palmitic acid, a saturated fatty acid, is ${\mathrm{C}}_{16}{\mathrm{H}}_{32}{\mathrm{O}}_2$.
​The formula for lauric acid, a saturated fatty acid, is ${\mathrm{C}}_{12}{\mathrm{H}}_{24}{\mathrm{O}}_2$.
​Saturated fatty acid stearic acid has the chemical formula ${\mathrm{C}}_{18}{\mathrm{H}}_{36}{\mathrm{O}}_2$.Unsaturated fatty acid linoleic acid with the formula ${\mathrm{C}}_{18}{\mathrm{H}}_{32}{\mathrm{O}}_2$.
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