Final answer:
The characteristic that does not characterize malignant metastasis is the proliferation of benign cells.
Step-by-step explanation:
Malignant metastasis is characterized by several factors, including invasion into surrounding tissues, angiogenesis (the formation of new blood vessels), and the formation of secondary tumors in distant sites. However, proliferation of benign cells does not characterize malignant metastasis. Benign cells do not have the ability to invade and spread to other parts of the body like malignant cells do. Therefore, the correct answer is C) Proliferation of benign cells.