When you have so many, it is convenient to use a spreadsheet or other technology to repeat the tedious task. See the table for the average rate of change.
It looks to me like the intervals you want are 2 3 4 5 1 6
D) There is no apparent association between the energy and light output. the image looks the most similar to a scatterplot with no relationship. im not finished with the test yet but im just trying to help anyone who might need it! i'll update with my test results.
