Which of the following lines includes a payment method object?

A.
$quote->getShippingAddress ( )->setPaymentMethod(isset ($data[‘method’]) ? $data[‘method’] : null); inside
Mage_Checkout_Model_Type_Onepage

B.
.public function setPayment(Mage_Sales_Model_Quote_Payment $payment) inside
Mage_Sales_Model_Quote

C.
$method = $this->getMethodInstance ( ); inside Mage_Sales_Model_Quote_Payment

D.
$instance->setInfoInstance($this); inside Mage_Payment_Model_Info