Which item sustained the least damage cost in the scenario described?

In the scenario described, the curtain sustained the least damage cost likely because it is typically less expensive to replace compared to the other items listed. Curtains are often made from relatively affordable materials, and their damage is generally less impactful, both in terms of repair and replacement costs.

The couch, window pane, and coffee table usually carry higher replacement or repair expenses. For instance, a couch can be a significant investment, depending on its size and material. Likewise, a window pane involves not only the cost of the glass itself but also labor for installation, which can add to the overall expense. The coffee table, while potentially less expensive than a couch or window, often still holds more value than a simple curtain.

By considering the construction material, replacement process, and overall value of these items, it becomes clear that the curtain represents the least financial impact when damage occurs.