E7F05 — Amateur Extra Class

E7F05 : How frequently must an analog signal be sampled to be accurately reproduced?
A At least half the rate of the highest frequency component of the signal
B At least twice the rate of the highest frequency component of the signal
C At the same rate as the highest frequency component of the signal
D At four times the rate of the highest frequency component of the signal
Correct Answer: At least twice the rate of the highest frequency component of the signal