Renard manages an expensive restaurant that consistently makes money. However, the servers complain that their customers do not leave big tips very often. Since Renard agrees with his staff, he decides to add an automatic $20\%$ tip to each customer's bill. A month after this change, Renard is surprised to find out that the number of customers coming to eat at the restaurant has sharply declined.

Which is the BEST next step Renard can take to solve this problem?

A$)$ Research the reasons why customers have stopped coming in$.$

B$)$ Change the automatic tip to be only $15\%$ on groups of $6$ or more.

C$)$ Look for more customers who like the experience of fine dining.

D$)$ Increase the price of all food and drinks on the menu at the restaurant.