Catherine owns a duplex. She resides in one unit and rents the other. Her expenses need to be categorized as indirect (partly deductible) or direct (fully deductible). Choose the response that provides the best example of a direct expense. 1. A new roof for the duplex, installed after the tenant complained about a leak in their ceiling. 2. Replacement sidewalk leading up to the building. 3. A new window air conditioner installed in the tenant's unit. 4. Landscaping