Consider the clustered bar chart of the dashboard developed to monitor the performance of a call center: Houston Email Internet Software Dallas Austin $0520251015$ Number of Calls This chart allows the IT manager to O a$.$ identify the percent of customers who do not have one of the listed problems. O b$.$ identify the frequency of a particular type of problem by location. O c$.$ identify which city contains the most customers. O d$.$ identify how often a problem is related to hardware