What is Reddit's opinion of Anno's Mysterious Multiplying Jar?

From 3.5 billion Reddit comments

Slight clarificaton: 0! = 1, and then for a positive integer n, n! = n*(n-1)!.

This is useful later, because then you can do things like 7!/7!0! and have it make sense instead of being undefined.

One way you can look at n! is the number of permutations or ways to order n elements.

If there are 0 elements, well, that's it. There's only one way to arrange them: nothingness.

If there is 1 element, that's also it: only one way to arrange it.

Anyhow, others have already explained what the answer they're looking for is (C) and why it's wrong (C is the number of pizzas with 4 different toppings...though it's also the number of pizzas with 3 different toppings).

<u>Anno's Mysterious Multiplying Jar</u> is a great introduction to factorials, but at a K-2 level. The artwork is gorgeous, though.