I don't think control and turnout type were mentioned, I didn't read close after because I knew Elliot was right. But depending on equipment, an old 2 position e-unit and switch "at C" would do it old school style.
For reliability, I'd skip isolated rail triggers, the low wheel count and light weight of bump and go makes it sketchy. If the bumper option doesn't pan out (plenty of pressure; it already throws one switch... but mounting...? The PW lighted bumpers light would always blink when hit, but I'm not sure if that was by design or pressure disconnect from track.. If by design, a relay on n.open,to add power to the e-unit for a flash would work.
Otherwise a micro switch with a wire wisker throw arm would likely be my choice. Whatever method, note the switch must be at the far end of C so it cannot be thrown twice, once before and after the "bounce". However, mid run triggering between turnout and C could be done with a 3 position E-unit.
The e-unit itself is a mechanical latching vs electrical latching relay 
