Briefing Android Knowledge

What does the following code snippet do?

What does the following code snippet do?
iabHelper.startSetup(new
IabHelper.OnIabSetupFinishedListener() {
public void onIabSetupFinished(IabResult result)
{
if (!result.isSuccess()) {
……
} else {
……
}
});

A.
Check if a purchase is complete.

B.
Verify the credit card used is acceptable.

C.
Initialize billing setup within your application.

D.
Verify is amount is paid successfully.