A rectangular plot is 420 m long and 84 m wide. lt is surrounded by semi-circular flower beds along all its sides. The area of the entire plot (in hectares) is $$x$$. The value of $$x$$ (correct to one decimal place) is (Taken $$\pi=\frac{22}{7}$$):

A

19.1

B

18.7

C

17.9

D

19.4