Contact Inhibition Is Best Explained by Which Statement

Contact inhibition is best explained by which statement?

A) Contact between neighboring cells triggers reactions leading to inhibition of mitosis.
B) As neighboring cells become more tightly packed together, their size is restricted and cytokinesis can no longer occur.
C) As cell number increases, the protein kinases they produce compete with neighboring cells, inhibiting mitosis.
D) As cell number increases, the level of waste products increases, consequently slowing metabolism leading to mitosis.
E) As cell number increases, size restrictions inhibit protein synthesis.