please help me with the right option 14

Which statement(s) holds if a sample range which is lower than the lower controllimit on an R chart in which lower limit is zero Select one: O a. should be ignored because it signifies better than average quality O b. should be ignored unless another point is outside that limit O c. is impossible O d. should be investigated because an assignable cause of variation might be present O e. is an indication that no cause of variation is present