The question says; which of the following, if true, most strongly support the argument against Moviemania's claim.

So, we want something that will weaken Moviemania's argument of the critic.

Option A:- correct
If the other refreshments increased by less than 5%, but popcorn increases by 5%, then popcorn outperformed the other refreshments. It means popcorn sales were not hurt, relative to other refreshments. It weakens the Movemania's position and strengthens the critic, so this is the correct option

Option B:- Incorrect
Nowhere related t the argument which deals with popcorn sale.
This statement of the question deals permanently with sales of popcorn and businesses about it while this option contrasts between profits between beverages sold and movie tickets.

Option C:- Incorrect
Moviemania sold 5% more popcorn last year than in the previous year. It categorically means that the customers prefer popcorn popped in coconut oil to that of popcorn popped in canola oil. It strengthens Moviemania position in one way or the other. I make the option incorrect.

Option D:- Incorrect
The people have increased, but sales have gone down. But this still does not addresses individual components of the total sales. Popcorn sales can go up the other items sales may have declined. It rather strengthens the sentence.

Option E:- Incorrect
We are concerned about this year and the previous years, not anytime before then making this option incorrect.