Which of the following is the main advantage of transmitting power over transmission lines on high voltage?

Correct option is A

​$$\text{The main advantage of transmitting power over transmission lines at high voltage is that} \\\text{the efficiency of the transmission line is increased. This happens because:} \\[1em]\text{When power is transmitted at high voltage, the current in the line decreases for the same} \\\text{amount of power transmitted, as per the formula } P = VI \quad (\text{Power} = \text{Voltage} \times \text{Current}). \\[1em]\text{Lower current results in reduced } I^2R \text{ losses (where } I \text{ is the current and } R \text{ is the resistance} \\\text{of the line), which are the main source of power loss in transmission lines.} \\[1em]\text{Additionally, reduced current leads to smaller voltage drops across the line.}$$​​