That would be a relative pronoun
The answer is either C or D
The correct answer is C.
To determine the tone of a text, you have to look at the word choices of the text and see what effect they have on the text
Objective well-being
Many countries and private institutions are interested in knowing the well-being of their member constituents. Higher levels of objective well-being are usually characterized by higher educational attainment, safe neighborhoods, as well as economic sufficiency and stability, for instance.
