A.I. Explanation:

Option 1: "To showcase modern art from the Riverdale community"

Explanation: This option is incorrect because the text focuses on the historical aspects of Riverdale, specifically mentioning artifacts and stories from the past. There is no mention of modern art, making this option irrelevant to the exhibition's theme.

Option 2: "To promote Riverdale's future urban development plans"

Explanation: This option is incorrect as the text does not discuss any future urban development plans. Instead, it emphasizes the historical journey of Riverdale, which does not align with promoting future developments.

Option 3: "To enhance understanding of Riverdale's historical development"

Explanation: This option is correct because the text explicitly states that the exhibition explores Riverdale's history and aims to deepen the community's appreciation for its heritage. This aligns perfectly with enhancing understanding of the town's historical development.

Option 4: "To introduce new interactive technology to visitors"

Explanation: This option is incorrect because, while the exhibition includes interactive timelines, the primary focus is on historical understanding rather than the introduction of new technology. The text does not suggest that technology is the main objective of the exhibition.