If the long-run market supply curve for a good is perfectly elastic, an increase in the demand for that good will, in the long run, cause
选项：

A:an increase in the number of firms in the market but no increase in the price of the good.
B:an increase the price of the good and an increase in the number of firms in the market.
C:an increase the price of the good but no increase in the number of firms in the market.
D:no impact on either the price of the good or the number of firms in the market.