Which of these is an extrinsic effect on the skin?

The option indicating misuse of products as an extrinsic effect on the skin is correct because it involves external factors that can lead to skin issues. Extrinsic influences are those that come from outside the body, impacting its condition and appearance. When products are misused—whether through overuse, applying incorrect formulations for one's skin type, or using products inappropriately—this can cause adverse effects such as irritation, rashes, or allergic reactions.

In contrast, hormonal changes and genetics are intrinsic factors. Hormonal changes arise from within the body and can affect skin conditions, but they are not considered extrinsic as they do not originate from external sources. Genetics also stems from inherited traits that dictate certain skin characteristics and vulnerabilities; hence, they are also classified as intrinsic factors.

The other answer options, including smoking, while it is an external factor, is more about lifestyle choices that contribute to skin aging and damage rather than a direct misuse of skincare products. Therefore, the correct choice highlights the specific impact of improper product use on skin health.