Which of the following is not a reason for making a double mass curve analysis for gage consistency? (a) To adjust data because of frequent vandalism at the gage; (b) to estimate the areal average...

Which of the following is not a reason for making a double mass curve analysis for gage consistency? (a) To adjust data because of frequent vandalism at the gage; (b) to estimate the areal average rainfall; (c) to adjust for a change in exposure of the gage; (d) to adjust for change in observational procedures.