which is correct. $(1)$ In the early $1900$s$,$ conditions in America$$s slaughterhouses and packinghouses were enough to turn one$$s stomach. $(2)$ Since there was no law permitting the federal government to inspect the meat$-$packing industry, spoiled and diseased food often made its way onto American tables. $(3)$ Upton Sinclair$$s novel The Jungle contained graphic descriptions of the slaughter of cattle infected with tuberculosis, of meat covered with rodent droppings, and of men falling into cooking vats. $(4)$ When President Theodore Roosevelt received a copy of The Jungle, he was sickened by what he read. $(5)$ So was the public. $(6)$ Spurred by public outrage, the Pure Food and Drug Act of $1906$ sailed through Congress; the law prohibited allowing diseased and spoiled food in interstate and foreign commerce.

Question$1.$ Which sentence that states the problem in this paragraph?

a$.1$

b$.2$

c$.3$

d$.4$