How can the graph of f(x) = - x + 1 be obtained from the graph of y = 1x? O A. Shift it horizontally 1 unit to the right. Reflect it across the x-axis. O B. Shift it horizontally 1 unit to the left. Reflect it across the x-axis. O C. Shift it horizontally 1 unit to the left. Reflect it across the y-axis. O D. Shift it horizontally - 1 unit to the left. Reflect it across the x-axis