The correct answer is b, antigens
Answer
:When thermal energy is added to a substance, its temperature increases, which can change its state from solid to liquid (melting), liquid to gas (vaporization), or solid to gas (sublimation). ... When the pressure exerted on a substance increases, it can cause the substance to condense.
Cell controls on division contact with other cells once DNA (cell directions) is copied, cell divides sequence of steps
Region A, Hope this helps.