What is the definition of economic crisis according to the text?

I. Economic crisis is a result of an imbalance between the supply and demand of goods and services.
II. Economic crisis is a result of natural disasters such as floods and earthquakes.
III. Economic crisis is a result of political instability and population growth.
a) Only I is correct.
b) Only II is correct.
c) Only III is correct.
d) I and III are correct.
e) I, II, and III are correct.