Please show detailed help with steps and solution :

Apple Corp sold 80,000 units providing a profit of $60,000. The unit margin of safety for the period was 40,000 units. If the company increases its ad expenses next period by $20,000, its sales will increase to 100,000 units. What will be the new net income next period?

A) $70,000 B) $80,000 C) $90,000 D) $30,000 E) None

Thanks