[C#] questions

1. What print to console the following line Console.WriteLine(

1<<2-1

); ?
a. 2
b. 7
c. 4
d. 3

2. What is it in caption variable?
Hashtable m_idsToColumnsCaptions;
long valueId = 0l;
m_idsToColumnsCaptions = new Hashtable();
m_idsToColumnsCaptions.Add(valueId, "Hello");
string caption = m_idsToColumnsCaptions[(int)valueId] as string;

a. "Hello"
b. Throw an exception
c. null
d. System.String

3. What is the result of running the following line of code?

Console.WriteLine((string)null);

a. This line of code has a compile time error.
b. It throws a NullReferenceException
c. Write null to the console
d. an empty line is written to console

4. Giving the following sequence of code:

public class A
{
public A(string i_masagge) {}
}

internal class B : A
{
internal B() {}
}
what will happen?

a. it is compiling perfectly.
b. there is an access problem.
c. a compile error is thrown
d. a run time error is thrown.

Answers:
1. a.
2. c.
3. d.
4. c.