Even c may be too abstract, b was the clearest to me. I can see why if you’re completely familiar with your product you may prefer the others, because you feel it does so much more but for people who’ve never heard of a product it’s perhaps easiest to understand.

I have the same issue at Tesults.com. If someone’s never heard of it, I’d describe it as ‘test results reporting’ but yeah it’s a lot more than that, it’s a complete pipeline for handling post testing.