Over an eleven-month period, during which national retail computer sales remained stable at 400,000 units per month, sales by the Friendly Computer Stores chain rose 200 percent, increasing the chain's share of the total market to 7 percent. Other retail stores tried, without success, to attract customers away from the Friendly chain. Then regulation X was imposed on all computer retailers by the federal government. In the ensuing months, Friendly's total share of the market fell to 4 percent, even though its monthly sales volume remained at the same level it had reached just prior to the enactment of regulation X.

Each of the following, in conjunction with the information presented above, could be true EXCEPT:

(1) All other computer retailers experienced a drop in their sales volume during the four-month period following the enactment of regulation X.

(2) All other computer companies lost some market share during the four-month period prior to the enactment of regulation X.

(3) The enactment of regulation X provided the Friendly chain's competitors with an advantage they did not previously have.

(4) The enactment of regulation X did not provide the Friendly chain's competitors with an advantage they did not previously have; other dramatic changes in other market forces caused the decline in the Friendly chain's market share.

(5) In the period following the enactment of regulation X, many new computer retailers that specialized in low-budget computers entered the marketplace.

[spoiler]OA is D, while I selected A.
Please share your thoughts.
Source : Princeton[/spoiler]