What is the slope of the equation if the equation is wrong?

If the equation is wrong, the slope is also wrong. Either your work has not been completed correctly, or you're answering the wrong question.

The correct answer is letter C: It supports the myth by providing facts about how the Kiowas first named themselves with words that mean “coming out.” The historical manner in which the author explained the origins of the Kiowa gives a foundation as to the mythical descriptions that have been passed on from generations to generations. People are now more aware of the context and background of these native ancestors of the past.