The correct answer is: C. Either I or II follows.
The statement “Industrial Revolution which first of all started in Europe has brought about modern age” does not provide enough information to determine whether or not conclusion I (“Disparity between rich and poor results in revolution”) or conclusion II (“Revolution overhauls society”) follows.
Conclusion I could follow if we assume that the Industrial Revolution caused a great deal of disparity between rich and poor, and that this disparity led to revolution. However, the statement does not explicitly state that the Industrial Revolution caused disparity between rich and poor, or that this disparity led to revolution.
Conclusion II could follow if we assume that the Industrial Revolution caused a great deal of upheaval and change in society, and that this upheaval and change was revolutionary in nature. However, the statement does not explicitly state that the Industrial Revolution caused upheaval and change in society, or that this upheaval and change was revolutionary in nature.
Therefore, either conclusion I or conclusion II could follow, but we cannot say for certain that both conclusions follow.