For which operating system is exFAT NOT an option when formatting a partition?

A. Windows XP with SP3

B. Windows XP with SP2

C. Vista with SP1

D. Vista

To determine for which operating system exFAT is NOT an option when formatting a partition, we need to consider the supported file system options of each operating system listed.

A. Windows XP with SP3: exFAT is NOT natively supported in Windows XP. Therefore, it is NOT an option when formatting a partition on this operating system.

B. Windows XP with SP2: Similarly, exFAT is NOT natively supported in Windows XP with SP2. Hence, it is also NOT an option when formatting a partition on this operating system.

C. Vista with SP1: Starting from Vista with Service Pack 1, Microsoft introduced exFAT support, making it an option for formatting a partition on this operating system.

D. Vista: Similarly, exFAT is an option for formatting a partition on Vista as well.

Based on the above analysis, the answer is: B. Windows XP with SP2.