I want to know the answer to the following question:
When were the 3 new cemeteries open?
All the background I'm provided with is that "Open from 1804, these were the cemeteries of Père Lachaise, Montmartre, Montparnasse, and later Passy; these cemeteries became inner-city once again when Paris annexed all neighbouring communes to the inside of its much larger ring of suburban fortifications in 1860.". Is that enough to answer the question?
Answer: yes