Harsha made a wind chime using a frame and metal rods. She punched 8 holes in the frame, each 2 cm apart, and then hung 6 metal rods from the frame, as shown in the figure below. The ends of the metal rods are aligned over a line, shown by the dotted line in the figure.
If all of the rods are straight and not swaying, then what is the length of Rod P?
(a) 69/7 cm
(b) 53/5 cm
(c) 76/5 cm
(d) 111/7 cm