$*$CIVIL ENGINEERING$*$

In a two dimensional incompressible steady flow around an airfoil, the stream lines are $2$ cm apart at a great distance from the airfoil, where the velocity is $30$ m$/$sec$.$ The velocity near the airfoil, where the stream lines are $1\mathrm{.}5$ cm apart, is

A$.22\mathrm{.}5$ m$/$sec$.$

B$.33$ m$/$sec$.$

C$.40$ m$/$sec$.$

D$.90$m$/$sec$.$