in fact, you could get away here even w/o Python programming, just using 2 unix utilities:

1. jtm - that one allows xml <-> json lossless conversion
2. jtc - that one allows manipulating JSONs

Thus, assuming your xml is in file.xml, jtm would convert it to the following json:

bash $ jtm file.xml 
[
   {
      "quiz": [
         {
            "que": "The question her"
         },
         {
            "ca": "text"
         },
         {
            "ia": "text"
         },
         {
            "ia": "text"
         },
         {
            "ia": "text"
         }
      ]
   }
]
bash $ 

and then, applying a series of JSON transformations, you can arrive to a desired result:

bash $ jtm file.xml | jtc -w'<quiz>l:[1:][-2]' -ei echo { '"answer[-]"': {} }\; -i'<quiz>l:[1:]' | jtc -w'<quiz>l:[-1][:][0]' -w'<quiz>l:[-1][:]' -s | jtc -w'<quiz>l:' -w'<quiz>l:[0]' -s | jtc -w'<quiz>l: <>v' -u'"text"'
[
   {
      "answer1": "text",
      "answer2": "text",
      "answer3": "text",
      "answer4": "text",
      "text": "The question her"
   }
]
bash $ 

Though, due to involved shell scripting (echo command), it'll be slower than Python's - for 5000 questions, I'd expect it would run around a minute. (In the future version of the jtc I plan to allow interpolations even in statically specified JSONs, so that for templating no external shell-scripting would be required, then the operations will be blazing fast)

if you're curious about jtc syntax, you could find a user guide here: https://github.com/ldn-softdev/jtc/blob/master/User%20Guide.md