Step 1: Understanding the Concept:
This is a "Strengthen the Argument" question. We need to find the statement that makes Quintero's proposal more practical, feasible, or logical. Quintero's proposal is to use space in the high school (where enrollment is decreasing) to house elementary students (where enrollment is increasing).
Step 2: Detailed Explanation:
Quintero's plan depends on the assumption that there is available and suitable space in the high school. A statement that confirms this assumption would strongly support the proposal.
\begin{itemize}
\item (A) This weakens the proposal by pointing out a practical limitation. If rooms cannot be converted, the plan is less feasible.
\item (B) This information is irrelevant. The comparison is between building a new elementary school and converting existing high school rooms, not building two different types of schools.
\item (C) This might weaken the proposal. If the number of families choosing the high school is increasing, the high school might need its classrooms back sooner than expected, making the "temporary" conversion a poor long-term solution.
\item (D) This significantly weakens the proposal by highlighting a major potential downside related to student well-being.
\item (E) This strongly supports the proposal. It establishes that the high school has a surplus of space (classrooms that were "rarely needed"). The fact that this surplus existed even before the enrollment decrease means there is very likely a significant amount of empty space available now, making Quintero's plan to use that space highly practical and sensible.
\end{itemize}
Step 3: Final Answer:
The best support for Quintero's plan is evidence that the necessary resource—empty classrooms—actually exists. Option (E) provides this evidence directly, making it the correct answer.