Read the passage. (1) Artists were invited to create temporary installations in vacant storefront windows. (2) Each work remains for three months, after which the space may be leased or assigned to another artist. (3) The short display period limits permanence but allows organizers to test different themes, materials, and neighborhood partnerships. (4) [Revision point] The writer wants to acknowledge the installations' impermanence while explaining why that feature can be valuable. Which choice best accomplishes this goal?