Numex,an Equities Firm,requires Its Employees to Be Highly Analytical

Numex,an equities firm,requires its employees to be highly analytical.The company's HR department develops a series of tests to be used in the preliminary rounds of interviews to gauge the candidates' analytical skills.Before using it in the selection process,the HR department got some of the best analysts in the firm to take the test on different days of the week.Surprisingly,each of their scores was highly inconsistent on different days.After an evaluation,the test was found to be unreliable.Which of the following assumptions would lead to such a conclusion?

A) The analysts were randomly chosen.
B) The intelligence quotient levels of the different analysts are on par with each other.
C) The analysts have similar amounts of experience.
D) The on-job performance levels of the analysts decreased over the week.
E) The skills of the analysts remain constant over a week.