Chicago Division has a required rate of return of 15%. The weighted average cost of capital is 10%

Here is the information for Chicago Division operations:

Current Assets: $120,000

Long Term Assets: $220,000

Current Liabilities: $90,000

Long term Liabilities: $85,000

Operating income: $52,800

What was the Chicago Division's residual income?

a. $19,800

b. $34,800

c. $7,920

d. $1,800