The graph below illustrates the pulse height output of a gas-ionisation chamber as a function of DC voltage applied to the chamber electrodes. Voltage Pulse Height (Log Scale) ii. B E DC Voltage In each of the applied-voltage regions A, B, C, D and E: i. Describe what happens to the electrons and ions liberated within the gas in that region. If the device is used for measurement of y-radiation, what measurement application is that region is best suited for (e.g. is it used for pulse or current mode, for counting photons or spectroscopy etc.?).