Which of the following is a muscle in the human body?

The Deltoid muscle is a large triangular-shaped muscle that lies over the glenohumeral joint and which gives the shoulder its rounded contour. It is comprised of three distinct portions (anterior or clavicular, middle or acromial, and posterior or spinal) Acts mainly as an abductor of the shoulder and stabilizer of the humeral head. as well as assists in forward elevation. The deltoid is a very powerful muscle and is used in many ADLs (eg putting clothes online, carrying shopping bags, washing hair) and many athletic activities.

Source: Physiopedia