An $n$-channel $\text{JEFT}$ has $\mathrm{I}_{\mathrm{DSS}}=2 \mathrm{~mA}$ and $\mathrm{V}_{p}=-4 \mathrm{~V}$. Its transconductance $\mathrm{gm}$ (in milliohm) for an applied gate-to-source voltage $\mathrm{V}_{\mathrm{GS}}$ of $-2 \mathrm{~V}$ is
- $0.25$
- $0.5$
- $0.75$
- $1.0$