What proportion of elected officials in the United States represents single-
member districts?

B across local, state, and federal levels

Explanation:

A single-member district (single-member constituency) is an electoral district that sends one officeholder to a body. In America, state legislatures and the united state congress are both elected from single-member districts.

In the United States, single member district has been used to elect across all levels i.e. local, state and federal because it makes sure that communities which are small in size and population are represented in legislative assemblies.

the two things that develop a strong social foundation are: a. separation of church and states e. education received attention separation of church and states separate the illogical  argument that came from religious beliefs to a fact based belief. while education will make us remember the past to avoid the repeat of our mistakes.