Answer:
C. The cost of a box of cereal
Step-by-step explanation:
In the question, we are given the number of 3 boxes of cereal, 2 loaves of bread, and that the total cost is $15. We can see these numbers in the equation, and putting it into context, we see that the 15 is on the right side of the equation, which indicates cash. Therefore, the 3 and 2 are accounted for, but their prices are unknown. X is a placeholder for the unidentified cost of a box of cereal, and we know that it's the boxes of cereal and not the loaves of bread because there are 3 and not 2.