Which of the Following Contributed to the Fighting Style of the Plains

Which of the following contributed to the fighting style of the Plains Indians?

A) Chinese immigrants introduced gunpowder in the nineteenth century.
B) The Spanish introduced horses in the sixteenth century.
C) Hessian soldiers introduced firearms in the eighteenth century.
D) The French introduced swords in the sixteenth century.
E) English setters introduced them to the bow and arrow in the seventeenth century.