Why Can Cancer Cells Proliferate in the Absence of Serum

Multiple Choice

Why can cancer cells proliferate in the absence of serum?

A) Their nuclei depend on these serum growth factors to maintain their structure.
B) The serum inhibits their growth,while it is necessary for normal cells.
C) The cell cycle of cancer cells does not depend on signals transmitted from serum growth-factor receptors located at their surface.
D) The cell cycle of cancer cells depends on signals transmitted from serum growth-factor receptors located in their cytoplasm.
E) Their mitochondria depend on serum growth factors for their activity.