Hey,

I am flying to Frankfurt with Lufthansa, and connecting in Dulles. My inbound United Flight from Atlanta I believe will arrive at the C or D gates, and I need to get to the B gates for Lufthansa.

How best to connect? AirTrain or Sky Lounge?
I will be traveling alone with two children. 1.5 years and 5 years. My connection time is 1h 50 minutes.