A built up edge is formed while machining

A conventional lathe and a $$CNC$$ lathe are under consideration for machining a given part. The relevant data are shown below :

The machine preferred for producing $$100$$ pieces is

Deep hole drilling of small diameter, say $$0.2$$ $$mm$$ is done with $$EDM$$ by selecting the tool material as

Abrasive material used in grinding wheel selected for grinding ferrous alloys is