**Core Concept**
Ribs are a pair of long, curved bones in the thoracic cage that play a crucial role in protecting the heart and lungs. They develop from somites, which are blocks of mesoderm that form in the embryo.

**Why the Correct Answer is Right**
During embryonic development, somites differentiate into sclerotomes, myotomes, and dermatomes. The sclerotomes eventually give rise to the vertebral bodies and ribs. Specifically, the ribs develop from the costal processes of the thoracic vertebrae, which are formed from the sclerotomes. This process involves the migration and differentiation of cells from the sclerotomes to form the ribcage.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the embryonic origin of ribs.
**Option B:** This option is incorrect because it refers to the development of long bones, which is a different process.
**Option C:** This option is incorrect because it refers to the development of the sternum, which is a separate structure from the ribs.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the ribs develop from the somites, which also give rise to the vertebrae and other components of the axial skeleton. This knowledge can be useful in understanding various congenital anomalies and skeletal disorders.

**Correct Answer: C. Somites. Embryonic somites give rise to the ribs, vertebrae, and other components of the axial skeleton.**