Answer:
Causal ambiguity.
Explanation:
Causal ambiguity occurs when a firm's product or services is hard to imitate because it is impossible for competitors to relate effects to an initial action.
This could also arise of a large number of competencies interact in a complex way to give performance.
For example when it is not clear if a firm's success is as a result of the competence of its management or just by sheer luck.