The most essential fatty acids are that fatty acids that are not synthesized in our body and must come from the food we eat. For example, Linoleic acid (Omega-6 fatty acid ) is a most essential fatty acid. Linolenic acid is found in vegetable oils such as sunflower, soybean, corn, and canola oils as well as nuts and seeds.
So, the correct answer is 'Linoleic acid'.