Feeding 12V Pulse into Microcontroller 5V - Use a Transistor?

I have a 12V Tachometer Pulse Signal From an ignition unit(From the data sheet)...I would like to feed this pulse into a micro-controller to output the speed to a LCD display. I don't have a scope to put on the 12v signal, but I did put it on a multimeter and the frequency matches what I was expecting. Albeit, the signal is a bit jumpy.

What's the right way to connect this pulse into MCU? Optoisolator?

Is this a safe way to connect the 12v Pulse into the MCU? Should I use a voltage divider on the pulse?

^{simulate this circuit – Schematic created using CircuitLab}