The correct answer is option 1: wisdom teeth. Wisdom teeth are the third set of molars that humans develop in their late teens or early twenties. These teeth were useful in our ancestors who had larger jaws and needed the extra teeth for chewing tough foods. However, as our jaws have evolved to become smaller over time, there is often not enough space for wisdom teeth to fully emerge. As a result, they can become impacted, causing pain, infection, and other dental problems. Because of these issues and the overall lack of need for wisdom teeth in modern humans, they are considered vestigial organs. Vestigial organs are remnants of structures that were functional in ancestral species but have lost their original purpose in the course of evolution.