most susceptible to them? ESTJs get angry way too easily, but I wouldn't call them "susceptible" because if someone shows emotions around them they're not likely to be pierced by them.
I went with ESTP too. The ETPs and ITPs are the only ones with a conscious Fe function, and the ITPs have it inferior. It was then a toss-up between S/N, then, but I figured that Ne would make the ENTPs more likely to react to the idea of emotions, while an S would react if they could see a person were showing emotions in front of them.
It really depends on what you mean by susceptible too, though. Most likely to have their minds changed by others' feelings? Most likely to feel something themselves? Most likely to demonstrate empathy? I'd give different answers for each. The ESTP response was based on the "having their minds changed by someone else showing feeling in front of them" interpretation.