Which of the following is NOT an interface declared in System.Collections namespace?

1. The ArrayList class contains an inner class that implements the IEnumerator interface.
2. An ArrayList Collection cannot be accessed simultaneously by different threads.
3. The inner class of ArrayList can access ArrayList class's members.
4. To access members of ArrayList from the inner class, it is necessary to pass ArrayList class's reference to it.
5. Enumerator's of ArrayList Collection can manipulate the array.

1. It can be used for evaluation of expressions.
2. All elements in the Stack collection can be accessed using an enumerator.
3. It is used to maintain a FIFO list.
4. All elements stored in a Stack collection must be of similar type.
5. Top-most element of the Stack collection can be accessed using the Peek() method.

1. Map
2. Stack
3. BitArray
4. HashTable
5. SortedList

1. Stack
2. Queue
3. BitArray
4. ArrayList
5. HashTable

1. Map
2. Stack
3. Queue
4. BitArray
5. HashTable

Queue q = new Queue(); 
q.Enqueue("Sachin"); 
q.Enqueue('A'); 
q.Enqueue(false); 
q.Enqueue(38); 
q.Enqueue(5.4);

IEnumerator e;
e = q.GetEnumerator(); 
while (e.MoveNext())
Console.WriteLine(e.Current);

IEnumerable e;
e = q.GetEnumerator(); 
while (e.MoveNext()) 
Console.WriteLine(e.Current);

IEnumerator e;
e = q.GetEnumerable(); 
while (e.MoveNext()) 
Console.WriteLine(e.Current);

IEnumerator e;
e = Queue.GetEnumerator(); 
while (e.MoveNext()) 
Console.WriteLine(e.Current);

Stack st = new Stack();
st.Push(11);
st.Push(22);
st.Push(-53);
st.Push(33);
st.Push(66);

IEnumerable e;
e = st.GetEnumerator(); 
while (e.MoveNext())
Console.WriteLine(e.Current);

IEnumerator e;
e = st.GetEnumerable(); 
while (e.MoveNext())
Console.WriteLine(e.Current);

IEnumerator e;
e = st.GetEnumerator(); 
while (e.MoveNext()) 
Console.WriteLine(e.Current);

IEnumerator e;
e = Stack.GetEnumerator(); 
while (e.MoveNext()) 
Console.WriteLine(e.Current);