An airplane engine manufacturer developed a new engine model with safety features lacking in the earlier model, which was still being manufactured. During the first year that both were sold, the earlier model far outsold the new model; the manufacturer thus concluded that safety was not the customers' primary consideration.

Which of the following, if true, would most seriously weaken the manufacturer's conclusion?

• ABoth private plane owners and commercial airlines buy engines from this airplane engine manufacturer.  
• BMany customers consider earlier engine models better safety risks than new engine models, since more is usually known about the safety of the earlier models.  
• CMany customers of this airplane engine manufacturer also bought airplane engines from manufacturers who did not provide additional safety features in their newer models.  
• DThe newer engine model can be used in all planes in which the earlier engine model can be used.  
• EThere was no significant difference in price between the newer engine model and the earlier engine model.