A bundle of muscle fibers is a(n):

Choice A reason: Flat bones are typically thin and broad, such as the sternum or skull bones. They do not match the described dimensions of Emily’s bone.

Choice B reason: Irregular bones have complex shapes that do not fit into other categories, such as vertebrae. The bone described is not irregular.

Choice C reason: Short bones are roughly cube-shaped and found in areas like the wrist and ankle. A bone that is 3 inches long does not fit this category.

Choice D reason: Long bones are characterized by being longer than they are wide, typically found in the limbs. A bone that is 3 inches long and 1 inch wide fits this classification.

Choice E reason: Sesamoid bones are small, round bones embedded in tendons, like the patella. The described bone does not fit this category

Choice A reason: The sternum is a flat bone located in the center of the chest and forms part of the thoracic cage, which protects vital organs such as the heart and lungs. The clavicle, or collarbone, is part of the pectoral girdle and connects the sternum to the scapula, helping to stabilize the shoulder.

Choice B reason: Both the scapula and clavicle are components of the pectoral girdle. This choice does not correctly identify a structure from the thoracic cage.

Choice C reason: The clavicle belongs to the pectoral girdle, and the sternum to the thoracic cage. This choice reverses the correct anatomical relationship.

Choice D reason: The scapula is part of the pectoral girdle, and the sternum is part of the thoracic cage. However, this pairing does not match the structure-to-system relationship asked in the question.