The correct answer here is: "at large", as in "at large election" - option C.
An election "at large" refers to an election that chooses representatives to represent the whole body - rather than just a part of this body, as as a district.
The opposite is voting by electoral districts.
The most basic definition of fertile is "being able to produce offspring". In humans this means being able to have children, and in other species, such as plants, it means being able to reproduce: by producing seeds for example.
