The sides of a triangular grass plot are 20.4 m, 28.5 m and 32.6 m, respectively. A goat is tethered to a stake within the plot. Find the minimum length of the rope tied so the goat so that it can graze over the entire plot.
A. 12.54
B. 15.67
C 16.47
D. 17.27
C 16.47