In an exponentially growing batch culture of $\text{Saccharormyces cerevisiae}$, the cell density is 20 ${gl^{-1}}$ (DCW), the specific growth rate ($\mu$) is 0.4 ${h^{-1}}$ and substrate uptake rate (v) 1s 16 $gl^{-1}h^{-1}$. The cell yield coefficient $Y_{x/9}$, will be

1. 0.32
2. 0.64
3. 0.80
4. 0.50