Correct option is (c) Hydraulic ash handling system
For explanation: Since the hydraulic ash handling system involves the usage of liquids, the discharging sites cannot be re-located/re-placed. Else constructing/developing a new discharging site is possible but the old one cannot be replaced since it is a wet system. In case of all other forms of ash handling system it is easy since they are dry system and they won’t have much of an impact on the following discharging site/land.