Where did Einstein work checking patents?

Correct answer: Swiss Patent Office

Einstein worked at the Swiss Patent Office, where he examined patent applications and technical ideas, so option A is correct. This employment was an important stage in his life because it provided regular work while leaving him intellectual time for scientific thinking. The office was not a military department, so option B is incorrect. There is also no account of him checking patents at a London bank or working in a Paris museum; options C and D are invented alternatives designed to test careful recall. A useful distinction is that the question asks for the workplace, not the city. The workplace was the Swiss Patent Office, and the city associated with that office was Bern. Keeping the institution and location separate helps answer both this question and the next one accurately.