After Salome dances for Herod, he offers her one half of his ____, but instead of his kingdom she asks for the head of John the Baptist. A. travesty B. domain C. potion D. collusion
"After Salome dances for Herod, he offers her one half of his" would be the best fit, since in this setting "domain" refers to a large area of land, usually under the control of a single ruler or entity.
