What major type of rock is most likely to experience brittle deformation

Please correct me if I'm wrong but I believe that igneous rock is most likely to experience brittle deformation.

The truman doctrine was an american foreign policy whose stated purpose was to counter soviet geopolitical expansion during the cold war. it was announced to congress by president harry s. truman on march 12, 1947, and further developed on july 12, 1948, when he pledged to contain threats to greece and turkey