Horizontally arranged subexercises (1a, 1b, 1c, 1d etc.)

[jonascj]

First of all, great work, thank you.

What would be an approach to have multiple columns of short exercises, like in the image below? It seems like a waste of space to have one whole line for 5 symbols, but it would also be nice to have them numbered and handled by the xsim package.

Is it a a \begin{exercise}...\end{exercise} for each of the many small exercises, or is it one exercise environment containing another enumerative environment?

[jonascj]

Closing because my request/question isn't well-formulated. I'll open another.