Final answer:
If the student didn't open the check envelope or refused to check their mail, the income recognition would be deferred until the check is received.
Step-by-step explanation:
If the student didn't open the envelope containing the check, it would mean that they haven't received the funds yet. In this case, the income recognition would be postponed until they actually open and cash the check. Income is recognized when it is received, not when it is sent.
If the student refused to check their mail in the last week of December and the check remained unopened, the income recognition would still be deferred since the funds haven't been received. The act of checking the mail or not doesn't actually affect the timing of income recognition.