How do you allow the caller to submit a variable number of arguments to a function?

Consider the following table data and PHP code. What is the outcome?
Table data (table name "users" with primary key "id"):

PHP code (assume the PDO connection is correctly established):
$ dsn = 'mysql:host=localhost;dbname=exam';
$ user= 'username';
$ pass='********';
$ pdo = new PD0($dsn, $user, $pass);
try {
$ cmd = "INSERT INTO users (id, name, email) VALUES (:id, :name, :email)";
$ stmt = $pdo->prepare($cmd);
$ stmt->bindValue('id', 1);
$ stmt->bindValue('name', 'anna');
$ stmt->bindValue('email', '[email protected]');
$ stmt->execute();
echo "Success!";
} catch (PDOException $e) {
echo "Failure!";
throw $e;

Which interfaces could class C implement in order to allow each statement in the following code to work?
(Choose 2)
$ obj = new C();
foreach ($obj as $x => $y) {
echo $x, $y;

What is the difference between "print" and "echo"?

Which of the following is NOT possible using reflection?