Which of the following is the correct way to declare an integer variable in C#?

• int number;

• integer number;

• num number;

• var number = "int";

What is the default value of a string variable in C# if it is not initialized?

• 0

• null

• ""

• "undefined"

Which data type would you use to store a value like 3.14 in C#?

• int

• string

• double

• bool

What is the output of the following code? ```csharp int x = 5; int y = 2; Console.WriteLine(x + y); ```

• 7

• 52

• 3

• 10

Which of the following is a valid way to assign a value to a property named `Text` of a label called `label1` in a Windows Form?

• label1.Text = "Hello";

• label1->Text = "Hello";

• label1.text("Hello");

• label1.Text: "Hello";

Which keyword is used to declare a variable whose value cannot be changed after initialization in C#?

• static

• const

• var

• readonly

What is the correct way to convert an integer variable `num` to a string in C#?

• num.ToString();

• ToString(num);

• string(num);

• num.toString;

Which of the following is a boolean data type value in C#?

• "true"

• 1

• true

• "yes"

What is the correct way to declare a variable that can store a single character in C#?

• char letter;

• string letter;

• character letter;

• chr letter;

In a Windows Form application, which property would you update to change the background color of a form named `Form1`?

• Form1.Text

• Form1.BackColor

• Form1.Size

• Form1.Visible