In a digital system, a 1 is a high voltage (approx ??V) and a 0 is a low voltage (approx ??V). What are the typical voltage values for a high (1) and a low (0) in digital systems?

a) 1V and 0.1V
b) 5V and 2V
c) 0.5V and 1V
d) 3.3V and 0V