PLI Corporation had net fixed assets of $2,500,000 at the end of 2006 and $1,800,000 at the end of 2005. In addition, the firm had a depreciation expense of $200,000 during 2006. Using this information, how much was PLI's net fixed asset investment for 2006?

a) $ 700,000

b) $ 900,000

c) $ 500,000

d) $ 850,000

e) None of the above