Answer: b) Becky's environment
Step-by-step explanation:
According to the question, environment of Becky is the cause on ineffective performance as her desk is in crowded place with lot of disturbance in her surroundings. Thus, she keeps getting interrupted in her work which leads to in-completion of task on timely manner.
Other options are incorrect because ineffectiveness in performance of Becky is not due to ability, cognitive ability and motivation of Becky.Thus, the correct option is option(b).