Concept: Chronological order means arranging events according to time, starting from the earliest event and moving toward the latest event.
Step 1: Identify the year of each disaster.
The Gujarat Earthquake occurred in 2001.
The Indian Ocean Tsunami occurred in 2004.
Hurricane Katrina occurred in 2005.
Cyclone Nargis occurred in 2008.
\[
\text{Gujarat Earthquake} = 2001
\]
\[
\text{Tsunami} = 2004
\]
\[
\text{Katrina Hurricane} = 2005
\]
\[
\text{Nargis Cyclone} = 2008
\]
Step 2: Arrange them from past to present.
The earliest event is Gujarat Earthquake. After that came the Tsunami, then Katrina Hurricane, and finally Nargis Cyclone.
\[
2001 < 2004 < 2005 < 2008
\]
Step 3: Write the order using the given letters.
Gujarat Earthquake is D.
Tsunami is C.
Katrina Hurricane is A.
Nargis Cyclone is B.
Therefore, the correct order is:
\[
D, C, A, B
\]