Final answer:
A Leiomyoma is a benign neoplasm of smooth muscle, distinguishing it from malignant and skeletal muscle tumors. Option a is the answer.
Step-by-step explanation:
The benign neoplasm of smooth muscle is called a Leiomyoma. This type of tumor is noncancerous and does not exhibit the aggressive, invasive behavior that characterizes malignant neoplasms. In contrast, Leiomyosarcoma represents a malignant tumor of smooth muscle, while Rhabdomyosarcoma and Rhabdomyoma pertain to neoplasms of skeletal muscle rather than smooth muscle, with the former being malignant and the latter benign. So the correct answer to the question is "A. Leiomyoma".