Are the United lounges in terminal A, B or C

Both are incorrect. There's no such thing as "Terminal A, B, or C" There's the Main Terminal, where there are no airline-specifc lounges. Then there are Concourses A, B, and C. United has a presence at both Concouses A and B, however both of its lounges are located in Concourse B--one on each side.

Terminal B West near gate 32 and Terminal B East near gate 44

Terminal B