The correct answer is: B. Windows 2000.
Windows 2000 was the first version of Windows to support 64-bit processors. It was released in 1999 and was a major upgrade from Windows NT 4.0. Windows 2000 was designed to be a reliable and secure operating system for businesses. It included a number of new features, such as support for multiple processors, Active Directory, and the Internet Information Services (IIS) web server.
Windows 98 and Windows 95 were both 32-bit operating systems. They were released in 1998 and 1995, respectively. Windows 98 was an upgrade from Windows 95, and it included a number of new features, such as support for USB devices and the ability to run multiple applications at the same time. Windows 95 was the first version of Windows to be based on the Windows NT kernel. It was a major upgrade from Windows 3.11, and it included a number of new features, such as support for a graphical user interface (GUI), multitasking, and 32-bit applications.
In conclusion, the only Windows version that supports 64-bit processors is Windows 2000.