You are migrating a solution to Windows Azure. The solution includes a web application and a business logic layer. The web application runs on three dual-core servers. The business logic layer runs on two quad-core servers. The Windows Azure application must match or exceed the current hardware specifications. You need to recommend role instance sizes that minimize cost. What should you recommend？（）

A. Small for the web application and Medium for the business logic layer
B. Small for the web application and Large for the business logic layer
C. Medium for the web application and Large for the business logic layer
D. Large for the web application and Extra Large for the business logic layer