Suppose the drift velocity vd in a material varied with the applied electric field E as: vd∝√E. Then V - I graph for a wire made of such a material is best given by?

The current I in a conductor is given as I=neAvd.. (i)
Given, vd∝√E.. (ii)
From relation (i) and (ii) the current I∝√E
The potential difference can be given as: V=El, wherel is the length of conductor and E is uniform electric field over length l.
So, I∝√V ⇒V∝I2
The relation between V and I is a parabola concave upwards.
Hence correct answer is option A.