It's a bit tough.
Email Send program should show this on the Dashboard.
You can also use the Constraint in the Was Sent Email filter to see actual people.
Not in the one report unfortunately. You can get email performance by segmentation for dynamic content but unfortunately not by test variant.
If you need more stats than the dashboard gives you, this is how I do it. Build two Email Performance Reports locally under your email program, and use Josh's suggestion above to build a smart list in each one with "Was Sent Email" as the filter and the constraint of "Test Variant", in which you would write A or B (or more if you have more test variants).