Final answer:
A metastatic malignant tumor has spread to other tissues or organs, a common feature of advanced cancer, frequently corresponding with stage 4 of the disease. The answer is option A.
Step-by-step explanation:
A metastatic malignant tumor is one that has spread to other tissues or organs. Metastasis is the process whereby cancer cells travel from the primary tumor site through the bloodstream or lymphatic system to form new, secondary tumors in different locations in the body. This can occur in various types of cancers and is a hallmark feature of cancer progression.
The common sites where metastases occur include the brain, lungs, bones, and liver. When cancer has metastasized, it generally signifies an advanced stage of the disease and is often associated with stage 4 cancer, which carries a poorer prognosis compared to cancers that have not spread.