In a water park there is a children's pool in the shape of a right circular cylinder, 1 m deep and with a volume equal to $12 \mathrm{~m}^{3}$, whose base has radius $\mathbf{R}$ and centre $\mathbf{O}$. It is desired to build a dry leisure island inside this pool, also in the shape of a right circular cylinder, whose base will be at the bottom of the pool and with the centre of the base coinciding with the centre of the bottom of the pool, as shown in the figure. The radius of the leisure island will be $r$. It is desired that after the construction of this island, the space intended for water in the pool has a volume of at least $4 \mathrm{~m}^{3}$. Consider 3 as an approximate value for $\pi$. To satisfy the given conditions, the maximum radius of the leisure island $\mathbf{r}$, in metres, will be closest to (A) 1.6. (B) 1.7. (C) 2.0. (D) 3.0. (E) 3.8.
In a water park there is a children's pool in the shape of a right circular cylinder, 1 m deep and with a volume equal to $12 \mathrm{~m}^{3}$, whose base has radius $\mathbf{R}$ and centre $\mathbf{O}$. It is desired to build a dry leisure island inside this pool, also in the shape of a right circular cylinder, whose base will be at the bottom of the pool and with the centre of the base coinciding with the centre of the bottom of the pool, as shown in the figure. The radius of the leisure island will be $r$. It is desired that after the construction of this island, the space intended for water in the pool has a volume of at least $4 \mathrm{~m}^{3}$.
Consider 3 as an approximate value for $\pi$.
To satisfy the given conditions, the maximum radius of the leisure island $\mathbf{r}$, in metres, will be closest to
(A) 1.6.
(B) 1.7.
(C) 2.0.
(D) 3.0.
(E) 3.8.