Where is the option for grease pencil convert to curve 2.78a I have drawn a few lines holding the D key. Now I want to convert it to a path or a curve but I can't find these options in the properties panel (N). Where are these options in Blender 2.78a?
This function is not in the properties panel (N) but in the tools panel (T). Open it up and scroll down to the Grease Pencil tab on the left. At the bottom of the Grease Pencil panel you can find Convert to Geometry.... Click it and you can choose whether you want to convert it to a polygon curve, a path or a bezier curve.