Identify the correct expression for the induced velocity by a semi-infinite vortex filament at a point.(Where symbols have their usual meaning)

• A. V= ( frac { Gamma }{4h} )
• B. V= ( frac { Gamma }{2h} )
• C. V= ( frac { Gamma }{2 pi h} )
• D. V= ( frac { Gamma }{4 pi h} )