Final answer:
A broken door is a curable functional obsolescence, as it can be repaired or replaced to restore its functionality.
Step-by-step explanation:
A curable functional obsolescence refers to a problem with a property that can be fixed or remedied. Out of the given options, the broken door would be a curable functional obsolescence. A broken door can be repaired or replaced, restoring its functionality. On the other hand, a split floor plan, outdated appliances, and a leaking basement would likely require more significant renovations or replacements to address the functional obsolescence.