The correct answer is b) hamstrings.
When considering the quadriceps as the prime movers for knee extension, it’s important to understand how muscles work in pairs. The quadriceps muscle group, located at the front of the thigh, is responsible for extending the knee joint. Opposing this motion are the hamstrings, which are located at the back of the thigh and are responsible for bending the knee. Therefore, the hamstrings act as the antagonists to the quadriceps during knee extension.
In contrast, the tibialis anterior is primarily involved in dorsiflexion of the ankle, the gluteus maximus is mainly involved in hip extension, and the soleus plays a role in plantarflexion of the ankle. Thus, among the options provided, the hamstrings are the primary antagonist during knee extension.