Model which states decline in extra time needed to produce last unit, every time for cumulative quantity of doubled units produced is classified as

incremental unit average model
incremental cost learning model
incremental unit time learning model
incremental price learning model

The correct answer is C. incremental unit time learning model.

An incremental unit time learning model is a type of learning model that states that the extra time needed to produce the last unit of a product decreases every time the cumulative quantity of doubled units produced increases. This means that the more units that are produced, the less time it takes to produce each additional unit.

This type of model is often used in manufacturing and production settings, where it can help to improve efficiency and reduce costs. It can also be used in other settings, such as software development, where it can help to improve the speed at which new features are developed.

The other options are incorrect because they do not accurately describe the incremental unit time learning model. Option A, incremental unit average model, is a type of learning model that states that the average time needed to produce a unit of a product decreases every time the cumulative quantity of units produced increases. Option B, incremental cost learning model, is a type of learning model that states that the cost of producing a unit of a product decreases every time the cumulative quantity of units produced increases. Option D, incremental price learning model, is a type of learning model that states that the price of a unit of a product decreases every time the cumulative quantity of units produced increases.