An old, two-storey house that you have just inspected only has one electrical outlet in the living room. The cost of installing more outlets is greater than the added value and other existing items will still maintain their value if the work is not done. This is an example of:
1. Curable deficiency requiring a substitution.
2. Curable deficiency requiring modernization.
3. Curable deficiency requiring an addition.
4. Incurable deficieincy.