SAT Question 1d945139: Ratios Rates Proportional Relationships And Units answer and explanation with Desmos solution

Choice D is correct. It's given that the total mass, in kilograms, of $r$ identical objects is $t$. To obtain the expression $146r$, $r$ is multiplied by $146$. Therefore, to find the total mass, in kilograms, of $146r$ of these objects, $t$ must also be multiplied by $146$. The result of multiplying $t$ by $146$ is the expression $146t$. Therefore, the total mass, in kilograms, of $146r$ of these objects, is $146t$.