Which term can be used to best describe the relationship between

Which term can be used to best describe the relationship between the underlined adjectives in “Unlike her gregarious sister, Jane is an unsociable person”?（ ）
A、Synonymy.
B、Antonymy.
C、Homonymy.
D、Polysemy.
【正确答案】：B
【题目解析】：gregarious 社交的，群居的；unsociable 不爱交际的。这两个词是一组反义词。即使不了解意义，也可以从“Unlike”判断出来。