Consider the following method, which is intended to count the number of times the letter "A" appears in the string str. public static int countA(String str)
{
int count = 0;
while (str. length() > 0)
{
int pos = str. indexOf("A");
if (pos >= 0)
{
count++;
/* missing code */
}
else
{
return count;
}
}
return count;
}

Which of the following should be used to replace /* missing code */ so that method countA will work as intended?

A) str = str. substring(0, pos);
B) str = str. substring(0, pos + 1);
C) str = str. substring(pos - 1);
D) str = str. substring(pos);
E) str = str. substring(pos + 1);