How do you answer a call with a physical keyboard? My Nexus 5 (Android 4.4.4) touchscreen has stopped working, and the warranty replacement is still a few days away.  Since I don't have any other phone to put my SIM in, I still have to use this phone even though the touchscreen doesn't work.

I discovered I can plug in a physical USB keyboard with an OTG adapter, and this suffices to navigate around the phone for the most part.  However I can't work out how to answer an incoming call using the keyboard!

Does anyone know what, if any, key combination you can press on an external (USB/Bluetooth) keyboard that will answer an incoming call?

(I worked out that Ctrl+Esc closes the lockscreen if there is no PIN set, but this does nothing when an incoming call is waiting to be answered.)
I don't know about keyboard shortcuts for answering a call on Android.

What you can do is to connect a USB mouse and use mouse gestures that replicate touch input, it is cumbersome but it should work. I've been doing that on a tablet with a similar problem.