SAT Question 1b403590: Ratios Rates Proportional Relationships And Units answer and explanation with Desmos solution

Choice A is correct. It's given that the object has a mass of $168$ grams and a volume of $24$ cubic centimeters. Dividing the mass, in grams, of the object by the volume, in cubic centimeters, of the object gives the density, in grams per cubic centimeter, of the object. It follows that the density of the object is $\frac{168\text{grams}}{24\text{cubic centimeters}}$, which is equivalent to $\frac{168}{24}$ grams per cubic centimeter, or $7$ grams per cubic centimeter.