It'd be nice to use Gapfill. The dropdown list is what we need here. Definitely. But.
First, until we won't move to LTS 3.5, no way (I've already discussed with the "system admins").
Second, I've tried in my Moodle 3.5 installation, but I could find out how to group the answers. Ok, I just gave a shot, and I should insist spending more time (but it's a bit "academy", since it's just to see where it takes me, how it works; at the end of the day, as I told, I have no chance to use Gapfill).
But I was surprised by his "sister", Word Select. Easy to work with, very accurate in the score (I have 15 items, 6 points - 0.4 per item - and it works perfectly).
So, I'm attaching 2 screens containing the 2 different solutions I' found out. In both cases, I have 15 "blanks" with 4 alternatives, so it's obvious that a dropdown list like in Gapfill would be the natural solution. But I'm confident it's fairly decent even like this. but I'm here to learn
Thanks for your participation. You're awesome!