LFS201 - Exercise 29.1

I'm confused by Docker exercise 29.1 in LFS201
It claims the correct answer is that "On a host system, Only one container of a given type can run at a time".

If that's the case, it wouldn't be possible to run two (or more) httpd instances on the same host when it clearly is:
$ alias d='podman'
$ d pull docker.io/httpd
$ d run -d --rm --name=ht1 -p 8000:80 docker.io/httpd
$ d run -d --rm --name=ht2 -p 8001:80 docker.io/httpd

This runs two instances of httpd which appears to contradict the answer the course system wants me to choose.

Could I please get some clarification as to what the question is actually after as running two containers off the same image (not sure what the authors mean by type).

Many thanks,
/Henrik