What is the region in which Omega signals are confined according to VLF wave guide model known as?

A)
Earth-Sea wave guide
B)
Sea-Ionosphere wave guide
C)
Earth-Atmosphere wave guide
D)
Earth-Ionosphere wave guide

Correct Answer :   Earth-Ionosphere wave guide


Explanation : In the wave guide model of VLF wave propagation the region in which the Omega signals are confined is known as the Earth-Ionosphere wave guide.