Question

what bone is highlighted red?
a scapula
b sternum
c vertebrae

Explanation:

The highlighted red bone in the image is the sternum. The sternum is a long, flat bone located in the center of the chest, connecting to the ribs. The scapula is the shoulder blade (not in the center chest), and vertebrae are the spinal bones (running vertically along the back, not the front - central chest as highlighted).

Answer:

b. Sternum