A Company is considering offering a wellness program to its 3000 employees in order to generate multiple benefits, including a reduction in healthcare costs. Before offering the program company wide, the Company has tested it by offering it to 500 randomly selected employees. Of those 500, 250 signed up for the program and 250 didn't. Over the next year, the average per person healthcare cost of the 250 who signed up for the program was approximately $300, while that of the 250 who didn't sign up was approximately $500. Clearly, offering the program company wide would result in reduction of healthcare costs.

Which of the following, if true, would must seriously undermine the force of the evidence presented?

A. For the year during which the wellness program was tested, the healthcare costs associated with some of the 2500 employees not offered the program were well under $300

B. Even after being made aware of the results of the test, many of the Company's employees indicated that they would not sign up for the program

C. At another company of similar size with no wellness program, the annual average per person healthcare cost is approximately $250

D. The average per person healthcare cost of the 2500 employees not offered the program was approximately $400 for the year over which the wellness program was tested

E. The 10 employees with the highest healthcare costs for the year over which the wellness program was tested were ones who had signed up for the program