The word “denaturalization” can be broken down into “de-”， “nature”， “-al”， “-ize”， “-ation”， each having meaning of its own. These minimal meaningful units are known as（） .

The word “denaturalization” can be broken down into “de-”， “nature”， “-al”， “-ize”， “-ation”， each having meaning of its own. These minimal meaningful units are known as（） .
A、morphemes
B、allomorphs
C、root
D、stem
正确答案：A