In a Task Analysis,what Are Competencies and How Are They

In a task analysis,what are competencies and how are they used?

A) Competencies are very similar to skills and are used in a very specific manner rather than a generalized one.
B) Competencies are behaviours that are used to distinguish effective performers from ineffective performers.
C) Competencies are related to knowledge, skills, behaviours and personality traits and are used to link training to organizational objectives.
D) Competencies are essential to develop observable performance behaviours which are used to replace all job descriptions.