Last year, fixed manufacturing overhead was $30,000, variable production costs were $48,000, fixed selling and administration costs were $20,000, and variable selling administrative expenses were $9,600. There was no beginning inventory. During the year, 3,000 units were produced and 2,400 units were sold at a price of $40 per unit. Under variable costing, net income would be a:

a. Profit of $6,000.

b. Profit of $4,000.

c. Loss of $2,000.

d. Loss of $4,400.

Can you help me understand how the answer of loss of 2,000 was reached?