Final answer:
The y-intercept of the graph representing the cost of cups of hot chocolate is 9, so the correct answer is B) 9.
Step-by-step explanation:
The y-intercept is the point where the line intersects the y-axis on a graph. Referring to the given graph representing the cost of cups of hot chocolate, the y-intercept is indicated as 9. Therefore, the correct answer to the question is B) 9. A slope of a line indicates that for every increase of 1 on the x-axis, there is a rise of 3 on the y-axis.
Since the line shown has a consistent slope along its length, the y-intercept is a fixed point and does not change regardless of the slope's value.