单选题 The word "nomadic" in the sentence "How is this affected by whether a bird is nomadic.?" can best probably mean ______.

A、 living in the north
B、 immigrant according to seasons
C、 'immigrant from place to place irregularly
D、 feather changing according to seasons

【正确答案】 C

【答案解析】从最后一段对Sedge Wrens这类鸟的描述they are thrown together with different birds every few months from all over the geographic range可以推断nomadic指的是一种不规律的迁徙，选项C正确。