The requirements for a web application state that it must be architected for high availability. The web application consists of front-end web server and back-end
database server components respectively. Which of the following describes a solution that meets this requirement, while minimizing costs?
A. One front-end web server and two clustered back-end database servers
B. Two front-end web servers and two back-end database servers
C. Two front-end web servers and one back-end database server
D. Two load-balanced front-end web servers and two clustered back-end database servers