Which description best characterizes skeletal, smooth, and cardiac muscle?

• A. Skeletal muscle is non-striated, involuntary, and single-nucleus.
• B. Smooth muscle is striated, voluntary, and multi-nucleated.
• C. Cardiac muscle is non-striated, involuntary, and lacks intercalated discs.
• D. Skeletal muscle is striated, voluntary, and multi-nucleated.

Answer: (D)