Multiple choice question with more than one mark for a choice

mcqmarks.exam

{
  name: "Demo Exam"
  duration: 0
  percentPass: 50
  shuffleQuestions: false
  navigation: {
    reverse: false
    browse: false
    showfrontpage: false
    onadvance: {
      action: warnifunattempted
      message: ""
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    onreverse: {
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    onmove: {
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  timing: {
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  feedback: {
    showactualmark: true
    showtotalmark: true
    showanswerstate: true
    allowreavealanswer: false
    advicethreshold: 50
  }
  questions: [
    {
      name: "A Question"
      statement: ""
      advice: ""
      variables: {}
      parts: [
        {
          type: m_n_2
          marks: 0
          prompt: "Which of these would be a good name for a dog?"
          minMarks: 0
          maxMarks: 4
          shuffleChoices: true
          displayType: checkbox
          displayColumns: 3
          choices: [ Jim, Fido, Mittens, "Woof Blitzer", Polly, "Indiana Bones" ]
          matrix: [ -2, 3, -1, 1, -1, 1 ]
          distractors: [ "_Jim_ is a name for a person", "_Fido_ is a classic dog name.", "_Mittens_ is more of a cat name", "_Woof Blitzer_! EXCELLENT!", "Calling a dog _Polly_ is just cruel.", "_Indiana Bones_ is a good name for a dog" ]
        }
      ]
    }
  ]
}