Does the sentence "Furthermore, in Britain the volunteer Observer Corps formed in 1925 provided a network of observation posts to report hostile aircraft flying over Britain." provide a valid answer to the question "Where was the Observer Corps based?"

A: yes

Does the sentence "According to Eurostat, the EU statistical agency, in 2012 the Commune of Paris was the most densely populated city in the European Union, with 21,616 people per square kilometre within the city limits (the NUTS-3 statistical area), ahead of Inner London West, which had 10,374 people per square kilometre." provide a valid answer to the question "What was the most populated city in the EU in 2012?"

A: yes

Does the sentence "As a result of the watershed's integrity and undisturbed natural water filtration system, New York is one of only four major cities in the United States the majority of whose drinking water is pure enough not to require purification by water treatment plants." provide a valid answer to the question "After the water purification plant at the Croton Watershed is built, how much more water will be added to the city's supply each day?"

A: no

Does the sentence "Sichuan came under the firm control of a Chinese central government during the Sui dynasty, but it was during the subsequent Tang dynasty where Sichuan regained its previous political and cultural prominence for which it was known during the Han." provide a valid answer to the question "Which empire ravished the Chengdu region with constant warfare and economic distress?"

A:
no