Question 9

Explanation

This question asks us to find the most correct conclusion based on the text. We can use mathematical logic principles to analyze the cause-and-effect relationships in the text.

The key statement in the text is:

"DAS damage ... is caused by rivers no longer being able to withstand rainwater discharge."

We can transform this into an implication form "If P then Q":

"If rivers are unable to withstand rainwater discharge, then DAS damage (or disaster) occurs."

Let's define the propositions:

• $p$: Rivers are unable to withstand rainwater discharge.
• $q$: DAS damage or disaster occurs.

The implication formed is $p \rightarrow q$.

In mathematical logic, an implication $p \rightarrow q$ is equivalent to $\sim p \lor q$ (Not P or Q).

Let's translate $\sim p \lor q$:

• $\sim p$: Rivers are able to withstand rainwater discharge.
• $q$: DAS damage or disaster occurs.

Thus, the equivalent sentence is:

"Rivers are able to withstand rainwater discharge or DAS damage/disaster occurs."

The answer choice that best fits this logical structure is:

"Rivers are able to withstand rainwater discharge damaged or disaster occurs during the rainy season."

The word "damaged" in the option likely refers to the DAS condition or is part of the "disaster occurs" phrase, but in terms of the "A or B" logical structure, this option is the only one that satisfies the equivalence $\sim p \lor q$.