According to the ohms law the current flowing in a current carrying conductor is directly proportional to the potential difference if other factors are kept constant.
The flow of current depends on the resistance of the conductor being used which is normally a constant, but with a number of factors such as the length, the cross section area among others. Increasing the length of a conductor increases the resistance while increasing the cross section area decreases the resistance. That is Rα l/A, where l is the length and A is the cross sectional area. Therefore, i believe the answer is shortening the conductor which means decreasing the length.