A coffee shop is selling their donuts for $1. In an average week they sell 300 donuts.For every $0.05 increase in price, the coffee shop will sell 20 less items. Which ofthe following revenue functions with respect to price increase is correct?a) R(n) = (1+0.05n)b) R(n)= (300 -0.05n)(1+20n)c) R(n) = (300- 20n)d) R(n)= (300-20n)(1+0.05n)