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 british won and the germans couldn't invade great brit

its perfect how it was