Answer: D- increase the net book value of plant assets when incurred.
Explanation:Plant Assets like property, plant, equipment are fixed assets and are referred to the resources that have physical substance. They are used in the running of a business and are not for customers sale.
-Additions and Improvements are the costs incurred to increase a plant assets by increasing efficiency and productiveness of the asset, they increase the net book value of plant assets when they are incurred leading to more productive facilities and output
