Answer: The correct answer to the question is option C
CELLS MUST FIRST ESCAPE THE BASEMENT MEMBRANE OF TISSUES.
Explanation: For any tumour cell to be able to gain entry into the lymphatic circulation or into the blood,there must first be an escape of the tumour cell from the basement membrane of the tissue it originated from,when the tumor first moves out if the basement membrane,it further moves through the extracellular space and then finds its way to the basement membrane of the vessel.
Spread of the tumour cells from it's point of origin (metastasis) is thought to involve the loss of cell to cell adhesion proteases and collagenases digestion of the basement membrane.
The basement membrane of the vessel can only be penetrated only if and after the basement membrane of the affected organ has been affected/breached.