You are designing the placement of the global catalog servers. You want to use the minimum number of global catalog servers that are required. Which design should you use?（）

• A、One global catalog server in New York.
• B、Two global catalog servers in New York.
• C、One global catalog server in Chicago and one global catalog server in New York.
• D、Two global catalog servers in Chicago and two global catalog servers in New York.
• E、One global catalog server in Chicago, one global catalog server in New York, and one global catalog server in Boston.