A is made up of a company, its suppliers, its distributors, and its customers who partner with each other to improve the performance of the entire system.

The correct answer is letter "D": value delivery network.

Explanation:

The value delivery network of a manufacturing company is formed by other entities that are part of its supply chain. The manufacturing firm establishes partnerships with those other companies so they can be involved in the production, distribution, and marketing of the products in cases where the main firm faces shortages or in an attempt of assigning them the responsibilities if certain functions at a lower cost.

answer(b); ; ; the quantitative or qualitative variable for which the experimenter wishes to determine how its value is affected by the explanatory variable;