The velocity components in the x and y directions for an incompressible flows are given as u = (-5 + 6x) and v = - (9 + 6y), respectively. The equation of the streamline is

• A. (-5 + 6x) - (9 + 6y) = constant
• B. \(\frac{{ - 5{\rm{\;}} + {\rm{\;}}6{\rm{x}}}}{{9{\rm{\;}} + {\rm{\;}}6{\rm{y}}}} = constant\)
• C. (-5 + 6x)(9 + 6y) = constant
• D. \(\frac{{9{\rm{\;}} + {\rm{\;}}6{\rm{y}}}}{{ - 5{\rm{\;}} + {\rm{\;}}6{\rm{x}}}} = constant\)