A stone is projected vertically upwards from a point $12\,\text{m}$ above the sea. After $3.4\,\text{s}$, it falls into the sea below. Air resistance is negligible. At what speed was the stone released when it was thrown?
- A$3.5\,\text{m s}^{-1}$
- B$6.6\,\text{m s}^{-1}$
- C$13\,\text{m s}^{-1}$
- D$20\,\text{m s}^{-1}$