2 of 7 added 13 characters in body

What would time be for 2D beings?

In my understanding of time as a dimension, every instant of our 3D world is just another slice of a 4D body, and we perceiving time is perfectly analogous to looking at a a succession of 2D scans of a 3D body.

A brain scan is a perfect example of this: the brain is examined from different planes and rendering these planes in succession makes it look like some kind of substance/ matter that changes over time.

Brain scan

If my above understanding is correct, is it also correct then that for a hypothetical 2D being, "time" would actually be the third dimension, not the fourth?