Final answer:
To analyze the cost between lotion C and D, we would need a graph or table of prices per volume. The slope of the lines would indicate cost per ounce, with a steeper slope signifying a higher cost. However, without specific data, we cannot definitively choose between the provided options.
Step-by-step explanation:
In order to determine the cost comparison between lotion C and lotion D, we would need to analyze the data provided which usually includes prices related to different quantities or sizes. We assume that there is a graph or a table that shows the cost of each lotion per given unit of volume. The slope of the lines on the graph would indicate the cost per ounce if we are plotting cost on the vertical axis and size on the horizontal axis.
If the slope of the line representing lotion C is greater than the slope for lotion D, that means for every ounce increased, the price of lotion C rises quicker than the price of lotion D, indicating that lotion C is indeed more expensive. Conversely, if for any given quantity, the line or value for lotion D is higher than that of lotion C, then it indicates that lotion D is more costly.
However, without specific data for lotions C and D, we cannot accurately choose between the given statements a, b, or c. Nonetheless, the concept regarding the slope of a line can be generally applied to understand price comparisons: a line with a steeper slope (greater slope value) suggests a higher cost per unit increase.
Understanding the slope as an expression of opportunity cost is crucial because it represents the cost of giving up one good in exchange for another, based on their respective prices and quantities represented on the graph. The opportunity cost can quickly be calculated by taking the price of one good divided by the price of the other, as indicated by the slope formula.