using System;

using System.Linq;                  

public class Program

{

    public static void Main()

    {

        string[] obs_section = new string[] {"a","b", "c"};

        string QS = $"'obs_section':[{string.Join(",",obs_section.Select(x => $"'{x}'"))}]";

        Console.WriteLine(QS);

    }

}