The largest buttock muscle

a. Gluteus maximus

b. Tibialis anterior

a. Gluteus maximus

Explanation:

The gluteus maximus muscle is one of the three gluteal muscles. As the name reflects, the gluteus maximus is one of the biggest muscle in the body. It is also heaviest muscle among the three gluteal muscles. The gluteus maximus is a superficial muscle of buttocks. Functionally, it serves as extensor muscle for femur bone of thighs.