Which one of the following parameters is accurate for DGPS ?

A. Positional accuracies ~ 1 – 2 m if rover is less than 1-2 km from the reference station
B. Positional accuracies ~ 2 – 5m if rover is less than 2-5 fm from the reference station
C. Positional accuracies ~ 5 – 10 m if rover is less than 5-10 km from reference station
D. Positional accuracies ~ 5 – 10 m if rover is less than 25 km