Final answer:
In level IV of the conscious-competence performance model, a performer is unconsciously competent. This means they can perform tasks proficiently without having to consciously think about them. The performer's ability at this level is not related to the ease of the task or the evaluation of performance. Option c is the answer.
Step-by-step explanation:
According to the conscious-competence performance model, in level IV of performance effectiveness, a performer is unconsciously competent. This level is characterized by the ability of the performer to execute tasks with a high degree of expertise without having to concentrate on the actions required. It signifies that the skills have become second nature, and the task can be performed with efficiency, often without conscious thought.
When someone is at this stage, neither 'individual performance cannot be evaluated' nor 'the task is easy' are relevant associations. The performer is proficient, which is unrelated to whether the task is objectively easy or the performance cannot be evaluated.
Thus, the correct answer to the question is: C) unconsciously competent, meaning none of the provided options (a. individual performance cannot be evaluated, b. the task is easy, c. both a and b, d. none of the above) accurately describe this level of the performance model.