Imo. E
Premise: New stores financed by investors have a much lower failure rate than stores financed by other means.
Conclusion: Source of financing, therefore, must be a more important causative factor in the success of a new store than are such factors as the location of the store, the quality of the staff, or the choice of merchandise.
Cause and effect: Source of financing leads success of new store rather than location of the store, the quality of the staff, or the choice of merchandise.
Potential weakener: 1) what if other mentioned factors leads to success of new store or
2) Another (new) factor leads to success of new store.
Which of the following, if true, most seriously weakens the argument above?
A. Investors tend to be more responsive than others to changes in a new store’s financial needs. - Out of scope as it's far away from conclusion.
B. The strategic planning of a new store is a less important factor in the long-term success of the business than are the personal characteristics of the owner. - Nothing about long term success of business mentioned in the paragraph.
C. More than half of all new stores close within three years. - Out of scope as it's far away from conclusion.
D. The management of new stores is generally less formal than the management of ongoing stores. - So, what? How it affects the conclusion? Wrong.
E. Investors base their decisions to fund new stores on such factors as the personal characteristics of the owner, location of the store, and marketing goals. - Yes, a few of other (mentioned) factors, i.e. personal characteristics of the owner and location of the store considered by investors prior to investing into new store. Hence, it weakens the conclusion.