Which of the following is an example of iterating through a container with an STL vector. typedef vectoriterator Iterator: int sum = 0; for (Iterator p = V.begin(); p != V.end(): ++3) return sum; typedef vector int>.iterator Iterator: int sum = 0; for (Iterator p = V.begin(); p != V.end(): ++p) sum += p; return sum; typedef vector<:iterator iterator: int sum="0;" p vendo return sum: o none of the above>