The cosmic microwave background (CMB) radiation is the afterglow from the Big Bang, and weak as it may be today, these primeval microwaves hold valuable information about fundamental properties of the early universe. Slight differences, or anisotropies, in the brightness and polarization of the CMB reveal clues about the nature of the primeval plasma: that the discrepancies exist at all shows that the plasma was not perfectly uniform. The variations in the brightness seen in the CMB reflect differences in the density of the primordial plasma, whereas the anisotropic polarization reveals information about the dynamics of the early universe, such as the movement of material and the number of gravitational waves. The CMB, however, is not the only source of polarized microwaves and the cosmological polarization must thus be measured at different wavelengths so as to isolate them from foreground signals.

Question: The wave lengths of the foreground signals are disregarded once they have been distinguished from the CMB.
Options:
A. true, B. false, C. uncertain
Answer: "C"