Explanation: Christians who originated primarily as the Jewish sect that followed Jesus Christ, as such, do not abolish the Old Testament. Christians fulfill the Old Testament together with the New Testament, so they follow the Ten Commandments. The Torah as the first five books of the Old Testament are also accepted by the Jews. The Jews believe in the covenant with God specifically established between Abraham and God through circumcision, and the promise that the blood descendants of Abraham will be the chosen people. Thus, the Jews believe that only the offspring of the Abrahamic line, the circumcised believers are the chosen people, while Christians believe in the New Testament that anyone who follows Christ has an alliance with God.
B. If you're referring to the Abrahamic Covenant (circumcise your kids because all Jews are Abram's grandkids) then yes. Christians don't acknowledge this, and anyone can enter Christianity through the sacraments.
