​What Type of Grinding Disk Must Be Used to Feather

Multiple Choice

​What type of grinding disk must be used to feather the edge of tack welds?

A) ​A standard grinding stone as long as the root opening has not decreased due to the tack weld shrinkage.
B) ​A thin grinding disk.
C) ​A new disk so it can reach all the way down into the groove.
D) ​A cupped disk so it is easier to work around the curve of the pipe.