Which of the following statements is true?

1.product costs affect only the income statement.
2.neither product costs nor period costs affect the statement of retained earnings.
3.this can also be a true statement if the period costs were prepaid (i. e., prepaid advertising, depreciation).
4.period costs affect only the balance sheet.
5.product costs eventually affect both the balance sheet and the income statement.
6.product costs affect only the balance sheet.