**Core Concept**
There are three main types of muscle cells, each with distinct characteristics, functions, and locations in the human body. These muscle cells are classified based on their structure, contractile properties, and innervation.

**Why the Correct Answer is Right**
The three main types of muscle cells are skeletal muscle cells (also known as striated muscle cells), smooth muscle cells, and cardiac muscle cells. Skeletal muscle cells are responsible for voluntary movements and are attached to bones via tendons. Smooth muscle cells are found in the walls of hollow organs, such as blood vessels, the digestive tract, and the urinary bladder, and are responsible for involuntary movements. Cardiac muscle cells are specialized for contraction and relaxation in the heart, pumping blood throughout the body. All three types of muscle cells are essential for maintaining various bodily functions.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it excludes smooth muscle cells, which are a distinct type of muscle cell.

**Option B:** This option is incorrect because it excludes skeletal muscle cells, which are another essential type of muscle cell.

**Option C:** This option is incorrect because it excludes cardiac muscle cells, which have unique properties and functions compared to skeletal and smooth muscle cells.

**Clinical Pearl / High-Yield Fact**
It is essential to remember that the three main types of muscle cells have distinct embryological origins: skeletal muscle cells arise from somites, smooth muscle cells arise from the mesoderm, and cardiac muscle cells arise from the splanchnic mesoderm.

**✓ Correct Answer: D. All of the above**