Final answer:
Activating either LH or RH ENG FIRE PUSH does not determine which Firex bottle squib is fired; both can discharge to the specified engine regardless of the switch activated.
Step-by-step explanation:
The selection of the LH or RH ENG FIRE PUSH switchlight does not determine which Firex bottle squib is fired because each bottle is designed to discharge through both the left-hand (LH) and right-hand (RH) nozzles, regardless of which side's ENG FIRE PUSH switchlight is activated. When you activate either the LH or the RH ENG FIRE PUSH switch, it triggers a release mechanism that disperses the extinguishing agent through the system to the specified engine. There's a specific protocol to be followed when addressing an engine fire, including the selection of which bottle to discharge first.