Please share your thoughts about the following.
I am having trouble understanding why almost everyone here https://english.stackexchange.com/questions/245059/correct-modal-verb chooses "could". One guy has suggested to ask here also.
It is possible for John to shift to architecture. John (should/could/must/might) shift to architecture.
So there are four options to choose from, please share your thoughts about why the 3 of them are not suitable and why 1 of them is the best answer.
Thanks!
UPDATE
What confuses me is the preference of "could" over "might". A guy from the other forum mentioned that if it still confuses me, I should ask here.