Consider That Extraneous Factors Might Affect a Worker's Performance

Consider that extraneous factors might affect a worker's performance. Why does pay based on performance increase the risk that the worker bears?

A) The extraneous factors can degrade or enhance the worker's performance.
B) The worker has asymmetric information about the extraneous factors.
C) The extraneous factors are unpredictable.
D) a and b.
E) a and c