Correct Option: B

Since here dependent source is connected in the circuit therefore Thevenin’s resistance, R_th is given by

Rth =	VOC
	ISC

Where,
V_OC = Open circuit voltage
I_SC = Short circuit current
Calculation of I_SC: Equivalent circuit is shown below.

ISC =	5V	= 2.5 mA
	2kΩ

Calculation of V_OC: Equivalent circuit is shown below.

5 = 2I + 3 V_AB + 1. I₁
or 5 = 6 I₁ + 2I₂ ....(i)
and 5 = 2I + 2I₂
or 5 = 4I₁ + 2I₁ ....(ii)
From equations (i) and (ii)
I₂ = 2I₁
and
I₁ = 0.5 mA
V_AB = V_OC = I₁ × 1kΩ
= 0.5 mA × 1 kΩ
= 0.5 V
Now,

Rth =	VOC	=	0.5
	ISC		2.5 × 10–3

or
R_th = 0.2 kΩ.