4L of 0.02 M aqueous solution of NaCl was diluted by adding one litre of water. The molality of the resultant solution is _____________.

Molarity =

0.02= , n is the number of moles of NaCl

n=.08

The volume of the solution is changed to 5L (4+1)

Molarity=

Thus, molarity is 0.016.

Thus, Option (iv) is the correct answer.