course "B" looks largely similar to the AQA syllabus, depending exactly on how they define what "made" modern Britain...
At the end of the day the content of your A-level is entirely irrelevant. You will study much more, and in much greater depth, at university. You can also do wider reading into the topics that don't overlap between the syllabuses and get an appreciation of both. The A-level is just a stepping stone, really.