What will be the output of the following C# code snippet?

static void Main(string[] args)
{
    StringBuilder sb = new StringBuilder("hello world");
    sb.Insert(6, "good");
    Console.WriteLine(sb);
    Console.ReadLine();
}

Which class in C# is used to read data from text files?

A. TextReader

B. FileReader

C. FileWriter

D. StreamReader

What is the purpose of the using statement when working with files in C#?

A. To read data from files

B. To write data to files

C. To ensure proper disposal of resources

D. To handle exceptions

In C#, which method is used to write data to a text file?

A. Write()

B. WriteLine()

C. WriteText()

D. Append()

What is the correct way to open a file for writing in C#?

A. FileStream file = new FileStream("filename.txt", FileMode.Write);

B. StreamWriter file = new StreamWriter("filename.txt");

C. File.OpenWrite("filename.txt");

D. None of the above