The thumb bone is part of the appendicular skeleton, while the sternum is part of the axial skeleton. Therefore, the correct answer to the above question is option b.
Explanation:
The human body is considered to have 206 types of bones. The skeleton system is considered to be the basic structure of the body. The whole skeleton system is comprised of bones. The whole skeleton system is divided into two reason which are appendicular skeleton and axial skeleton.
Axial skeleton consists of bones which are axial in nature and helps the human body to stand firm and straight on the ground. The “appendicular skeleton” consists of bones which are other than axial bones like hands, fingers, feet etc.
