A. 0-255
B. 0-511
C. 0-1023
D. 0-4095

Solution

C. 0-1023

Explanation

The analogRead method in an Arduino UNO returns a value in the range of 0 to 1023. This range corresponds to the analog input voltage between 0 and 5 volts, giving a resolution of approximately 4.9 millivolts per unit (5V/1024 units).