Which statement about trans isomers of unsaturated fatty acids is correct?

Trans isomers of unsaturated fatty acids are commonly known to have specific properties and health implications. Among the claims made, it is essential to identify which accurately describes their characteristics.

Trans fatty acids can serve to raise LDL (low-density lipoprotein) cholesterol levels while lowering HDL (high-density lipoprotein) cholesterol levels, which is not conducive to heart health. Hence, they are generally considered less healthy than their cis counterparts—the natural form of unsaturated fats—which are recognized for their potential health benefits, such as promoting heart health.

In terms of physical properties, trans isomers typically have higher melting points than cis isomers due to their straighter configuration, which allows for more compact packing of the molecules. This is the opposite of what is stated about melting points in the choices provided.

Considering these facts, the statement asserting that all answers are correct is invalid, as it contradicts the known properties and health implications of trans isomers compared to cis isomers. Therefore, while trans isomers have particular distinct characteristics, it is essential to critically evaluate each statement to determine accuracy, which may lead to choosing a more precise option rather than a blanket assertion of correctness.