Correct Option: B

For last line of Balmer series :
n₁ = 2 and n₂ = ∞

1	= RZ2		1	-	1		= R21		1	-	1
λB			n21		n22				22		∞2

λB =	4	...........(i)
	R

For last line of Lyman series : n₁ = 1 and n₂ = ∞

1	= RZ2		1	-	1		= RZ2		1	-	1
λL			n21		n22				12		∞2

λL =	1	...........(ii)
	R

Dividing equation (i) by (ii)

	=	4
λB		R
λL		1
		R

Ratio of wavelengths is

	λB	= 4
	λL