**Core Concept**
Protein synthesis is a crucial cellular process that involves the translation of messenger RNA (mRNA) into a polypeptide chain. This process occurs in specific organelles within the cell, where the necessary components for protein synthesis are assembled.

**Why the Correct Answer is Right**
The correct answer involves the ribosomes, which are complex organelles responsible for protein synthesis. Ribosomes read the sequence of nucleotides on the mRNA and assemble amino acids into a polypeptide chain. This process requires various factors, including transfer RNA (tRNA), aminoacyl-tRNA synthetases, and initiation and elongation factors. The ribosomes utilize the genetic code stored in the mRNA to select the correct amino acids for incorporation into the growing polypeptide chain. The ribosomes are found in both the cytoplasm and mitochondria, with the latter responsible for synthesizing proteins encoded by mitochondrial DNA.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the endoplasmic reticulum is primarily involved in protein folding, modification, and transport, rather than protein synthesis itself.
* **Option B:** This option is incorrect because the Golgi apparatus is involved in protein modification, sorting, and packaging, but not in protein synthesis.
* **Option C:** This option is incorrect because lysosomes are involved in cellular digestion and recycling, but not in protein synthesis.

**Clinical Pearl / High-Yield Fact**
Remember that the ribosomes are responsible for translating the genetic code into a polypeptide chain, and any defects in ribosomal function or structure can lead to various diseases, including ribosomopathies.

**Correct Answer: C. Ribosomes.