Question: In which city is the main U. S. office of this multinational diversified industrial company that merged Schroff GmbH located?
Sentence (from "Carl Zeiss AG"): There are currently two parts of the company, Carl Zeiss AG located in Oberkochen with important subsidiaries in Aalen, Göttingen and Munich, and Carl Zeiss GmbH located in Jena.
Relevant evidence: No