Another vote for B or D. I've been especially avoiding C during the construction because at times it has been pretty horrible. Precheck at both B and D tend to be pretty empty, and D has the advantage of being the first stop on the parking shuttle that I take into IAH. Although last week precheck at D was closed. They still allowed you to cut to the front of the line with precheck but unfortunately it was regular security from there. Not sure if that was a one-off or not?