Check here for instructional material to complete this problem. Use the slope formula to find the slope of the line that passes through the two given points. State whether the line is increasing, decreasing, horizontal, or vertical. (7,9) and (1,9) Select the correct choice below and, if necessary, fill in the answer box to complete your choice. O A. The slope is m = . (Type an integer or a simplified fraction.) O B. The slope is undefined. Is the line increasing, decreasing, horizontal, or vertical? O A. increasing O B. horizontal O C. vertical O D. decreasing