Please choice the correct answer. Please explain your answer.

Accrued salaries payable of $51,000 were not recorded at December 31, 2014. Office supplies on hand of $29,000 at December 31, 2015 were erroneously treated as expense instead of supplies inventory. Neither of these errors was discovered nor corrected. The effect of these two errors would cause

a. 2015 net income to be understated $80,000 and December 31, 2015 retained earnings to be understated $29,000.

b. 2014 net income and December 31, 2014 retained earnings to be understated $51,000 each.

c. 2014 net income to be overstated $22,000 and 2015 net income to be understated $29,000.

d. 2015 net income and December 31, 2015 retained earnings to be understated $29,000 each.