Final answer:
Leiomyosarcoma is the malignant tumor of smooth muscle.
Step-by-step explanation:
The correct answer is b.) Leiomyosarcoma.
This is a malignant tumor that arises from smooth muscle cells.
Smooth muscle is a type of muscle found throughout the body, including around various organs and tracts. It is responsible for involuntary movements, such as the contraction of the intestines.