There are three important keywords in this paragraph: the challenge posed by rural-urban continuum, the objective methodology with one or two metrics may not be enough to capture the wide diversity, it may require an element of human judgement. 2 captures all the keywords succinctly. 1 misses the element of human judgement, 3 also misses on the same. 4 goes out because it is not about the judgment of objective methodology, but human judgement coming as an additional factor to aid the methodology.