The correct answer is C) New immigrants lived in close-knit ethnic communities to support one another.
The statement that describes how optimism helped new immigrants endure the conditions described by Riis is "New immigrants lived in close-knit ethnic communities to support one another."
Jacob Riis (1849-1914) was an immigrant from Denmark that worked as a photographer and documented his photos of the terrible living conditions of poor immigrants.
He clearly wrote that "Their "large rooms were partitioned into several smaller ones, without regard to light or ventilation, the rate of rent
being lower in proportion to space or height from the
street; and they soon became filled from cellar to garret
with a class of tenantry living from hand to mouth, loose in
morals, improvident inhabits, degraded, and squalid as
beggary itself."
In those years in New Yor City, immigrants lived in communities to support each other and trying to better survive under harsh conditions.