Question: In which city are the headquarters of the multinational defence, security and aerospace company, one of the world's largest and ranked 3rd based on revenues in 2015, which has the subsidiary British Aerospace? 
Sentence (from "CAP Scientific"): In 1991 Sema Group put most of its defence operations (CAP Scientific Ltd and YARD Ltd) into joint venture with British Aerospace called BAeSEMA, which British Aerospace bought out in 1998.
Relevant evidence: No