Answer:
in my opinion, I would use a line chart since it visually expresses changes of a subject over time. It also shows plots the relationship between two variables.
(I explained the differences of the charts: *optional to read :)*)
Well, I doubt a pie chart would help. Pie charts just show percentages of 2+ variables. Say if 10 people had an option between cheese or pepporoni, a pie chart would just list how many (%) chose cheese or pepp.
A table would not help you visually see trends over time. Tables just help you list or log in things. Like logging in how many times you (insert activity here) every week.
An organization chart just helps you categorize your topics without it looking messy. So yeah, I'll stick with a line chart :D
