Power is transferred from system A to system B by an HVDC

Power is transferred from system A to system B by an HVDC link as shown in the figure given below. If the voltages V_AB and V_CD are as indicated in the figure, and I > 0, then

1. VAB < 0, VCD < 0, VAB > VCD
2. VAB > 0, VCD > 0, VAB < VCD
3. VAB > 0, VCD > 0, VAB > VCD
4. VAB > 0, VCD < 0

V_AB > 0 since rectifier output
V_CD > 0 inverter output
For I > 0, V_AB > V_CD,
hence only current will flow in the given direction.