Final answer:
Wi-Fi signal attenuation through a solid object is correctly classified as signal absorption. Other options provided such as scattering, refraction, diffraction, and reflection describe different interactions of wave behavior.
Step-by-step explanation:
When a Wi-Fi signal passes through a solid object and its strength is reduced, this phenomenon is known as attenuation. According to the options provided, the correct classification for this type of signal interference is absorption. Absorption occurs when the material of the object the Wi-Fi signal passes through absorbs some of the energy of the signal, causing it to weaken. Meanwhile, terms such as scattering, refraction, diffraction, and reflection describe other behaviors of wave interactions with materials and conditions. For example, refraction is when waves change their path at the interface of two media with different densities. Diffraction occurs when waves bend or scatter around small objects or openings, and this can lead to interference patterns characteristic of wave phenomena, as illustrated in the referenced Figure 29.17 and Figure 29.20.