如何使用Linq在JSon中检查标记

I have below JSon File :-

我有以下JSon文件:-

{
  "requirements": {
    "-FileName": "sample.xls",
    "requirement": [
      {
        "desc": "Employee status        will be classified as: 
•   Assigned $ when employee is working on a project. 
•   Reserved when employee is scheduled to work on a project in near future. Unassigned when employee is not working on project.",
        "Id": "Req40"
      },
      {
        "Id": "NFR-2",
        "desc": "Team Leader should create resource allocation $% request in Maintain Project Module. Resource allocation request $@is associated with only one role. Project $@ Manager should provide roll-on date and roll-off date in resource allocation request."
      },
      {
        "Id": "req2",
        "desc": "PRMS must always be available except during the & @ scheduled maintenance. Scheduled maintenance must always be at 8PM on week days.",
        "message": "message of Req3"
      }
    ]
  }
}
{