Correct Option: B

Given network

Y-parameter for network

Standard equations of Y-parameters are
I'₁ = Y'₁₁ V₁ + Y'₁₂ V₂ ........(i)
I'₂ = Y'₂₁ V₁ + Y'₂₂ V₂ .......(ii)
I'₁ = – I'₂ (from above circuit) ...........(iii)

Y'11 =	I1
	V1		v2 = 0

From above circuit V1 = 2 I'1 or	I'1	=	1	= 0.5 mho
	V1		2

or Y'₁₁ = 0.5 mho

Y'12 =	I1
	V2		v1 = 0

V₂ = I'₂ 2
or V₂ = – I'₁ 2

Y'12 =	I1	= –	1	= – 0.5 mho
	V2		2

Similarly

Y'21 =	I'2
	V1		v2 = 0

or Y'₂₁ = – 0.5 mho and

Y'22 =	I2
	V2		v1 = 0

or Y'₂₂ = 0.5 mho.
Now,

Y' =		0.5		–0.5		and
		–0.5		0.5

The new Y parameter
Y = Y' + Y''

or Y =		0.5	–0.5				2	4
		–0.5	0.5				1	3

or Y =		2.5		3.5		and
		0.5		3.5