Mayor: The annual rock festival held in our town has gained

The answer i think should be B
As the festival is popular and has attracted visitors, the mayor plans to increase the sales and increase the number of people coming to the fest by increasing the stages from one to three. The doubter comments that the visitors come to hear music and not the stages. The statement "The festival currently has to reject many quality bands because there is insufficient space and time for them to perform" will counter the doubter's comment that the extra stages will help in playing good music and since the fest is already popular, the chance of getting to hear good artists will increase the sales as per the Mayors' conclusion

A - There is no mention of the temporary beer and snack bars affecting the ticket sales and the people visiting the fest and hence can be marked incorrect
C- The festival having a high return visitor rate has no impact on increasing the number of stages as in this case, increasing the time of the fest would have been sufficient to attract more sales
D- There is no mention of the number of people visiting for business and no comparison can be drawn with respect to the increase in sales.
E- The conclusion is to increase the number of ticket sales and the point mentioned here does not come across as a counter to the doubter's comment