This is more
playing with words than a good question.
With modern
engines there are various ways to control surge, one of them is the use of blow
off valves (also called compressor bleed valves).
Engines with
electronic fuel control systems (all modern jet engines) the valves are
controlled by the fuel control unit, so we suppose that is the correct answer
that the CAA want.
The end
result will be that the blow off valve will reduce the pressure in the
compressor to prevent the surge.