Visa has used computer technology to reduce personal card processing time, replace cards in an average of $2$ days rather than $15$ days, drop response time to cardholder inquiries from $16$ to $10$ days, answer merchant inquiries in $4$ days rather than $14,$ and reduce emergency service for card replacement to within $24$ hours worldwide. Visa has improved its customer service by focusing on the $\_\_\_\_\_$ dimension of service quality

A$.$ Reliability

B$.$ Responsiveness

C$.$ Assurance

D$.$ Empathy

E$.$ Tangibles