Sorting MCQ questions alphabetically

I have a text file with MCQ's. after importing it every line got a separate cell
The questions are not numbered and do not have any spaces between them.

Some have ABCD. some have ABCD E as answers. As you see some questions have multiple lines (sometimes even 4 lines).. same holds for answers. The only thing that I can think of is that the first Letter of the question is Always capital and is never starting with the followin 3 characters "A. " or "B. " , "C. " or "E. " .. etc

This is a bout 150000 lines of data, and what I'm trying to achieve is each question in a separate cell (possibly using concatenate function and all the cells sorted alphabetically

they look in a similar format:

Someone with history of shortness of breath you would
suspect
A. asthma.
B. emphysema.
C. typhoid.
D. cardiac insufficiency.

so that they would look like "Someone with history of shortness of breath you would suspect A. asthma. B. emphysema. C. typhoid. D. cardiac insufficiency." all in one cell

Thanks , i would really appreciate any help I could get in achieving this