Make option models:-
{ _id: ''option 1', option: "option name", vote: 100
}
{ _id: ''option 2', option: "option name2", vote: 100 }
Make model for students: -
{ _id: 'student model object_id', name: "abc", options: [ { _id: 'option 1', name: 'option name', vote: 'yes/ no' // to ensure student check this option or not }, { _id: 'option 2', name: 'option name2', vote: 'yes/ no' // to ensure student check this option or not } ] }
Now by this you can also manage options easily and differ options student to student.