How C# project loads added references in 32 / 64 bit platforms?

Hi,

I have a C# library (Say A.dll) which had a reference of some dlls like System.Data, System etc. I build my project A.dll keeping target as AnyCPU in 32 bit dev machine.

Then I deploy A.dll to my 64 bit machine. Which bit (32 or 64 bit) System.Data / System dlls be referred by A.dll in my 64bit machine? How and at what time the choosing is done in my 64 bit machine?

Thanks