​The shoulders are protected by a triangle of muscle called this,which abducts the arm

A) ​abduction
B) ​anchor
C) ​aponeurosis
D) ​biceps
E) ​cramp
F) ​deltoid
G) ​dystrophy
H) ​gastrocnemius
I) ​gluteus medius
J) ​hamstring
K) ​hiccough
L) ​intercostal
M) ​musculoskeletal
N) ​pectoralis major
O) ​peristalsis

Deltoid

A large, triangular muscle covering the shoulder joint that is responsible for lifting the arm and giving the shoulder its range of motion.

Abducts

Refers to the movement of a body part away from the central axis or midline of the body.

Triangle

A polygon with three edges and three vertices, the simplest form of polygon in geometry.