Fotis is worried about distributed denial-of-service attacks against his company's primary web application. Which of the following options will provide the most resilience against large-scale DDoS attacks?

A content delivery network run by a major provider can handle large-scale DDoS attacks more easily than any of the other solutions. Using DDoS mitigation techniques via an ISP is the next most useful capability, followed by both increases in bandwidth and increases in the number of servers in the web application cluster.