Final answer:
Option (A), The small, membrane-bound component found inside of a eukaryotic cell is called an organelle. Organelles include structures like the nucleus and mitochondria, performing vital cellular functions.
Step-by-step explanation:
The question asks to identify what a small, membrane-bound component found inside of a eukaryotic cell is called. The correct answer is A. Organelle. An organelle is a structure within the cytoplasm of a eukaryotic cell that is enclosed within a membrane and performs a specific job. These structures are vital for a cell's function and include the nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, vesicles, and vacuoles.
It is important to note that although ribosomes are not enclosed within a membrane, they are still considered organelles in eukaryotic cells due to their crucial role in protein synthesis. The term 'eukaryotic cell' refers to cells with a true nucleus and other membrane-bound organelles, unlike prokaryotic cells which lack these membrane-bound subunits.