Answer : B. some of the police force
Among the choices above, it is the phrase in letter b wherein the pronoun "some" refers to a single noun which is " the police force". As you can see, the police force refers to a group of policemen making it a collective noun taking the singular form of the verb. The other objects of the pronoun "some" in the other options are all in plural form such as economy cars, native people, and the 6y foods.
The answer that would best complete the given statement above would be option A. Historical context. The political, economic, or cultural environment that surrounds an event provides the event with its historical context. Context<span> is the "setting" for an event that occurs, and the elements, conditions, and characteristics of this specific time will have an impact on the relevance of the event. Hope this answer helps.</span>