Which of the following fatty acids is polyunsaturated omega-6?

Linoleic acid is classified as a polyunsaturated omega-6 fatty acid due to its chemical structure and the position of the first double bond in relation to the methyl end of the carbon chain. Omega-6 fatty acids are characterized by having their first double bond positioned at the sixth carbon atom from the methyl end, which is precisely the case with linoleic acid. This particular fatty acid plays a crucial role in human health, as it is essential and must be obtained from dietary sources. It is involved in various physiological functions, including inflammation regulation and cell membrane structure.

In contrast, stearic acid is a saturated fatty acid with no double bonds, while oleic acid is a monounsaturated fatty acid with one double bond, and linolenic acid is a polyunsaturated omega-3 fatty acid, which means it has its first double bond at the third carbon from the methyl end. Thus, linoleic acid is the only correct answer here, as it fits the criteria for polyunsaturated omega-6 fatty acids.