Question

source: jacob riis, how the other half lives, 1890
one reason jacob riis published many photographs similar to this was to
disprove claims of yellow journalists
promote the use of child labor
increase public concern over tenement conditions
encourage government assistance for poor farmers

Explanation:

Jacob Riis was a muckraking journalist/photographer whose work How the Other Half Lives documented the squalid tenement living conditions of urban poor in late 19th-century New York. His goal was to draw public attention to these injustices to drive reform. The other options are incorrect: he did not disprove yellow journalists (he was an investigative journalist himself), he opposed child labor rather than promoting it, and his focus was on urban tenement dwellers, not poor farmers.

Answer:

increase public concern over tenement conditions