An n- channel JFET has IDSS=2mA,and Vp=-4v.Its transconductance gm=in mA/V)for an applied gate to source voltage VGS=-2v is___________?
A. 0.25
B. 0.5
C. 0.75
D. 1
A. 0.25
B. 0.5
C. 0.75
D. 1