I think it is worth having a chat to your tutor about the issues you are having with this course, as you are finding it necessary to ask for so much help on here.
Given that a few days ago you were doing questions on scatter graphs and lines of best fit I think that is what this question is expecting you to do. However I am not sure that it is a good approach for time series data. I am pretty sure you will find there is not a strong correlation between time and prices here.