Consider a class that uses the following variables to implement an array-based stack:

```
String [] s = new String[100];
int top = -1; // Note top == -1 indicates stack is empty

```

a method that implements a String peek() operation can be written as
A)
if (top == -1)
throw new RuntimeException("Empty Stack");
else
return s[top -1];
B)
if (top > -1)
return s[top];
else
throw new RuntimeException("Empty Stack");
C)
top--;
if (top == -1)
throw new RuntimeException("Empty Stack");
else
return s[top];
D)
if (top == 0)
throw new RuntimeException("Empty Stack");
else
{
top--;
return s[top];
}

B)
if (top > -1)
return s[top];
else
throw new RuntimeException("Empty Stack");