【单选题】

The heat generated by the operating system war between rivals IBMCorp. and MicrosoftCorp. is (21) .

Windows 95 and OS/2 introduce a new (22) .Both systems claim to multitask legacyDOS and 16-bit Windows applications. However, only OS/2 can provide full memory (crash) protection for these legacy applications because it is capable of running eachDOS and Windows application within its full-protected memory address space.
Windows 95 will run all current Windows applications in the same shared- memory address space, affording full memory protection only to the (23) 32-bit Windows 95 applications. In other word, Windows 95 users will have to (24) their current Windows applications to Windows 95 version to match the memory protection OS/2 now delivers.
While OS/2 does afford superior memory protection and multitasking for legacyDOS and Windows applications, it will not be able to run any Windows 95 applications. IBM may address this (25) in an update of the OS but has no present plans to do so.
A、upgradeB、upstair
C、downstair D、downgrade