(2020·高考全国卷Ⅱ·C片段)
The fur trade kept nutria in check for decades，but when the market for nutria collapsed in the late 1980s，the catsized animals multiplied like crazy.
30．What does the underlined word “collapsed” in Paragraph 5 probably mean?
A．Boomed. B．Became mature.
C．Remained stable. D．Crashed.
