I do not have the graph that you are referencing from this question to, but I can help you get led to the right answer. If the teacher exhibits the most variable year to year performance over a 5 year span, then the graph must show unstable fluctuating of figures. Those who are least variable would have a steady line going up or down or maybe even just straight.
C) The mean Value is closer to the middle of the range than the Median
Hope this helped!
Jamie because it’s showing you the same information but one in a table and on in a graph