During the year, Mason Company's current assets increased by $120,0, current liabilities decreased by $50,0, and net working capital

D-Increased by170

exple : CA =0  CL =100   WK= -100

                 =120         =50  WK =70   => inrease by170

D increased by $170

sorry i have no idea, but from the samples it,s 170 $.

Since Working Capital = CA - CL, when CA increase by $, CL decreae by $, the result is an increase in working capital by $

Agreed wtih Fajoul, The NWC will increase ! 

if current asset increase   then working capital increase

if current assret decrease then working capital decrease

if current liabilities  increase the working capital  decrease

if current liability  decrease then working  capital increaese

hennce asnwer  D. lncreased by $,0.