The cells of malignant tumors exhibit 
(a) Metastasis
(b) Contact inhibition
(c) Telomerase activity
(d) Anchorage dependence

Cells of malignant tumors lack contact inhibition and anchorage dependence. Cancer cells are characterised by high telomerase activity which enables the cells to divide indefinitely. Metastasis is the most feared property of malignant tumors. Cells sloughed from such tumors reach distant sites through blood, and wherever they get lodged in the body, they start a new tumor there.