The range, in mathematical terms, is only the y-values. So, what does this tell you? It tells you to focus on the y-values (The y values fall on the the vertical line/the line going up in down.). Now add the word function at the end. Range of the function. Translation = Y-values of the function.
According to the picture attachment, the line (in the terms of the y values only) starts at 0 and ends directly at 8, therefore the answer is A.