Answer: A
Step-by-step explanation:
According to Ohm's law, the current through a resistor is directly proportional to the voltage across it and inversely proportional to its resistance. Mathematically, Ohm's law can be represented as I = V/R, where I is the current, V is the voltage, and R is the resistance.
In this scenario, if the voltage across the resistor is increased by a factor of 2, the current through it will also increase. This is because the resistance of the resistor remains constant, and according to Ohm's law, an increase in voltage results in a proportional increase in current.
Therefore, the correct option is A. The current in the resistor is increased by a factor of 2.