Correct Option: B

Given : z =	3 + 4i
	1 - 2i

Rationalizing the denominator, we get

z =	3+4i	×	1+2i
	1-2i		1+2i

=	3 + 6i + 4i - 8
	5

=	10i - 5	= 2i - 1
	5

∴ Modulus of |z| = |2i - 1| √2² + (-1)² = √5