Words like foot or dog can each be used alone, and at the same time can form new words with other roots and affixes, e.g. footage and dogfight. This shows that the basic word stock has the characteristics of （ ）.

Words like foot or dog can each be used alone, and at the same time can form new words with other roots and affixes, e.g. footage and dogfight. This shows that the basic word stock has the characteristics of （ ）.

A.productivity

B.polysemy

C.collocability

D.​stability

正确答案是A