In the question below, three statements are given which may or may not contain an error in any part of the sentence. Identify the statements containing an error and also point out the part containing the error.

I) They are (A)/ doing it for the (B)/ soldiers in front of (C)/ them and the soldiers behind them. (D)
II) I am (A)/ living in (B)/ Gurgaon for (C)/ ten years. (D)
III) He has (A)/ been keeping (B)/ an eye on the Army (C)/ since the past 2 years. (D)