# When microwave signals propagate along the curvature of the earth,the effect is called

$\begin{array}{1 1}(a)\;\text{Faraday effect}\\(b)\; \text{Tropospheric scattering}\\(c)\;\text{Ducting}\\(d)\;\text{Reflection}\end{array}$

When microwave signals propagate along the curvature of the earth the effect is called ducting.
Hence (c) is the correct answer.