KPI's are descriped as:

A$.$ a mesure that tracks how well the organization or team is progressing toward a defined goal.

B$.$ a coding language that is often used for custom statistical analysis.

C$.$ a preconfigured, common filtering option that enables Excel users to quickly remove from view all data that does not meet some specified criteria.

D$.$ the effort required to understand something, such as a chart, due to its complexity.