The answer is A and D.
The relationship between power current and voltage is given by the following equation;
P=IV
P = power
V = voltage
I = current
When the voltage (V is increased and the current (I) is maintained, then the power will definitely increase.
Increasing the voltage also increases the distance that the power can be transmitted with little attenuation or loss. This is why voltage is usually stepped up (which will reduce current) significantly at power stations before it's transmission over long distances.