Which theory asserts that, in a two-party race, if voters select candidates on the basis of ideology and everyone participates equally, the party closer to the middle will win?

Middle voter theorem

Explanation:

Middle voter theorem is a theory on which most of the election depend. it stated that party that have median voter is going to be in power.

The two assumption on which Middle voter theorem depend is given below:

1) All the party candidate for particular constituencies are place along one side of political spectrum

2) voter's  have only preference to pick best from all given candidates list.

answer; i do believe its (b) 12.5 years of age;

we need the diagram to answer this correctly.