Ans . B

A]  Current density (J ) is given by

J = p* Vd          ----------------------- (1)

where,
p = charge density
Vd = drift velocity


B] Charge density is basically no. of charges present inside the material so it is given by.
p = n* q ---------------------------------(2)

where,
n = no. of charge carrier (say electron in our case)
           q = charge carried by charge carrier.

C] Drift Velocity is given by
Vd = u*E  -------------------------------(3)
where,
u = Mobility
E =  Electric field.

So J becomes,
J = n*q*u*E  -------------------(4)

D] Ohm's law according to classical electromagnetic theory is given by,
J = k*E -------------------------------(5)
where,
k = conductivity
E = Electric field.

 Equating 4 and 5 we have

k = n* q* u

for above question
  n = Nd as it is n-type semiconductor.
q = charge on electron = 1.6E-16
u = 1350
 substituting in equation (6) we get,

k = 9.2592 E+14
so answer is B