I would like to protect an ADC from ESD and Overvoltage by placing TVS diodes. After a bit of reading, configuration B seem to be the way to go for a differential AC signal. But I'm not competent enough to choose the diodes for this and having 6 of them does not help space/cost wise. So I went ahead and looked for an already-packaged IC, but most configurations of the ready-made ICs are configuration C. Such as TPD2E1B06 for 5V AC differential signal and TPDE007 for 12V AC differential signal; which is perfect for my applications.
Also the series resistor also plays an important role, as I have read that it also reduces the current stress these diodes will receive. At the same time I am using them to step down the voltage signal so I can read the 5V and 12V needed in my application. I would also like to know what would the best placement be in A or D or both but with half resistance.