The drain current of a MOSFET in saturation is given by $I_{D}=K\left(V_{G S}-V_{T}\right)^{2}$ where $K$ is a constant. The magnitude of the transconductance $g_{m}$ is
- $\frac{K\left(V_{G S}-V_{T}\right)^{2}}{V_{D S}}$
- $2 K\left(V_{G S}-V_{T}\right)$
- $\frac{I_{d}}{V_{G S}-V_{D S}}$
- $\frac{K\left(V_{G S}-V_{T}\right)^{2}}{V_{G S}}$