Which one of the following is a direct statement of Ohm's law?

• A. The voltage drop across a resistance is proportional to the value of resistance and the amount of current flowing through it
• B. The total resistance of a parallel circuit is less than the value of the smallest resistance
• C. The algebraic sum of voltages in a loop is equal to zero
• D. The algebraic sum of currents entering and leaving a point is equal to zero