  The B20 chiral magnets with broken inversion symmetry and C4 rotation
symmetry have attracted much attention. The broken inversion symmetry leads to
the Dzyaloshinskii-Moriya that gives rise to the helical and Skyrmion states.
We report the unusual magnetoresistance (MR) of B20 chiral magnet
Fe0.85Co0.15Si that directly reveals the broken C4 rotation symmetry. We
present a microscopic theory, a minimal theory with two spin-orbit terms, that
satisfies all the symmetry requirements and accounts for the transport
experiments.
