（）is a way in which new words may be formed from already existing words by subtracting an affix which is thought to be part of the old worD.

（）is a way in which new words may be formed from already existing words by subtracting an affix which is thought to be part of the old worD.
A.back-formation
B.affixation
C.insertion
D.addition
正确答案：back-formation