Not to be so much of a smartie pants - but probably neither.
From my experience, test kits (despite claims) are not about accuracy. It's about precision in connection with the performance of your livestock. So I've had API tests read 10 and 11 alk...but livestock had open polyps, growth and development, and decent color. For me, I worry less about getting an accurate result, and more about repeated performance.
So maybe I get consistent alk test of 12dkh. Everything is happy. Then I get alk test of 13 or 14...or maybe the other direction, 7 or 8. It's then that I'm gonna be worried.
There Is a extensive thread on accuracy vs precision that was very helpful
