Would deal with determining the age structure of a city's residents.
a. ecology b. anthropology c. biology d. demography

Option D, Demography. I’ll go over why the other three options are wrong.

Ecology studies organisms and how they react to each other, not the age structures of cities!

Anthropology is the study of humans from the past, which doesn’t really have anything to do with the ages of people in a city.

Biology studies life and organisms, but doesn’t specifically cover ages of people in a city.

Demography, on the other hand, is the study of statistics of populations of humans. Obviously, this option is the correct option.

-T.B.

nucleic acid molecules are incredibly complex, containing the code that guarantees the four different nucleotide units comprise dna, the nucleic acid of interest to the genealogist. and one of four nitrogen-containing molecules called nucleotides