Correct choice is (c) 5V/1024
The best explanation: The Arduino converts all analog voltages (0V to 5V or 3.3V) taken as input into a range of 0 to 1023. This is done by mapping the voltage levels. On the Arduino Uno the maximum voltage level is 5V and the onboard ADC has a resolution of 10 bits which means it can divide the analog signal it receives into 210 levels.