Final answer:
Sensitivity analysis is a technique used to see how changes in key assumptions impact results, useful in business and engineering for scenario planning and decision-making.
Step-by-step explanation:
The term sensitivity analysis best describes option A: It is a testing technique to determine how results would differ if key assumptions are changed. Sensitivity analysis is used in various fields, including business, finance, economics, and engineering, to assess how the outcome of a model or system would change based on variations in input parameters. It helps decision-makers understand the robustness of their decisions and prepares them for a variety of potential scenarios. For example, in financial modeling, sensitivity analysis can show how changes in interest rates or market conditions could affect a company's future revenue projections. Similarly, in engineering, it could be used to understand how the performance of a structure would vary with different material properties.