Choose your answer from:
(A). Wi-Fi;
(B). photons;
(C). antennae;
(D). energy;
(E). Heart rate;
(F). fire;
(G). layers of fat;
(H). electricity;
Q: Fact 1: Electricity is used as an energy source by electrical devices. Fact 2: Devices such as pagers and cell phones are forbidden. Given the two facts above, what is used as an energy source by pagers?
A:
(H).