Ques. Select the word or phrase which best expresses the meaning of the word typed in bold: The economic cataclysm which followed the industrial revolution brought with it complex problems hitherto unknown.

Op 1: Depression 
Op 2: Boom 
Op 3: Regeneration 
Op 4: Sudden and violent change

Solution:

Option:4 (Sudden and violent change)

a sudden violent upheaval, especially in a political or social context.