a woman at a point A on the shore of the circular lake shown in the figure wants to arrive at the point C on the lake diametrically opposite A$.$ She first rows a boat from A to B at a rate of $3$ mph and then jogs from B to C at a rate of $6$ mph part $2$ of $2$

$($ii$)$ If the lake is $2$ miles in diameter, what

is the least time she can take in getting from

$A$ to $C$ via $B?$

least time $=\frac{1}{3}\sqrt[\phantom{2}]{3}$ hours

least time $=\frac{1}{18}(6\sqrt[\phantom{2}]{3}+)$ hours

none of these

least time $=\frac{2}{3}$ hours

least time $=\frac{1}{6}$ hours

least time $=\frac{1}{12}$ hours