Concept: Risk perception gap means the difference between actual disaster risk and how people perceive that risk. A higher gap means people may underestimate or misunderstand the actual risk more strongly.
Step 1: Understand what decreasing order means.
Decreasing order means arranging from the highest value to the lowest value.
\[
\text{Decreasing order} = \text{Highest} \rightarrow \text{Lowest}
\]
Step 2: Compare the given regions.
The regions are:
\[
A = \text{Northern Africa}
\]
\[
B = \text{Northern America}
\]
\[
C = \text{Latin America and Caribbean}
\]
\[
D = \text{Australia \& New Zealand}
\]
Step 3: Arrange according to decreasing risk perception gap.
The correct decreasing sequence is:
\[
D \rightarrow A \rightarrow C \rightarrow B
\]
This means Australia & New Zealand comes first, followed by Northern Africa, then Latin America and Caribbean, and finally Northern America.
Therefore, the correct answer is:
\[
D, A, C, B
\]