Which BEST describes how the sand castle in the passage symbolizes Selena's past?

The sand castle symbolizes Selena's past by representing the fragility and impermanence of her childhood memories. Just as the sand castle is subject to the tides, her past is shaped by fleeting moments that can easily be washed away. This imagery reflects her nostalgia and the inevitable changes she faces as she grows, highlighting the bittersweet nature of reminiscing about a time that can never be fully reclaimed.