A very common way to form new words in English is to add affixes to existing forms. For example, "teacher" is formed by adding the affix -er to the existing form "teach"， and "enlarge" is created by adding the affix en- to the existing form "large".

A very common way to form new words in English is to add affixes to existing forms. For example, "teacher" is formed by adding the affix -er to the existing form "teach"， and "enlarge" is created by adding the affix en- to the existing form "large". These affixes are called ______ affixes.

A.inflectional

B.derivational

C.grammatical

D.morphological

正确答案是D