Answer:
D. $30,000 overstated
Step-by-step explanation:
Understatement of ending Inventory overstate the value of cost of Goods sold and understate the value of Net income and retained earning as well.
Overstatement of ending Inventory understate the value of cost of Goods sold and overstate the value of Net income and retained earning as well.
In 2016 the net income and retained earning was understated by $120,000.
In 2017 the net income and retained earning was overstated by $150,000.
Net Effect of both event in Retained earning at January 1, 2018
$150,000 overstated - $120,000 understated = $30,000 overstated