Which of the following correctly matches the three primary muscle tissue types with their voluntary status and whether they are striated or nonstriated?

• A. Skeletal muscle is voluntary and striated; Cardiac muscle is involuntary and striated; Smooth muscle is involuntary and nonstriated.
• B. Skeletal muscle is voluntary and striated; Cardiac muscle is involuntary and striated; Smooth muscle is voluntary and nonstriated.
• C. Cardiac muscle is voluntary and striated; Skeletal muscle is involuntary and nonstriated; Smooth muscle is involuntary and nonstriated.
• D. Skeletal muscle is involuntary and nonstriated; Cardiac muscle is voluntary and striated; Smooth muscle is involuntary and striated.

Answer: (A)

The key idea is that muscle tissues differ in both control and appearance. Skeletal muscle fibers attach to bones and are under conscious (voluntary) control, and they show clear striations from the organized arrangement of contractile proteins (sarcomeres). Cardiac muscle powers the heart and contracts automatically, so it is involuntary, but it is still striated because its cells share the same sarcomere organization; it also has intercalated discs that coordinate beating. Smooth muscle forms the walls of hollow organs and vessels, contracts without conscious control, and is nonstriated because its fibers lack the regular sarcomere pattern.

The statement that matches all of these features—skeletal muscle is voluntary and striated; cardiac muscle is involuntary and striated; smooth muscle is involuntary and nonstriated—is the best description. The other options mix up voluntary status or striation for one of the tissue types.