The velocity measured by the tube is , nearly,

Question

A glass tube with a 90⁰ bend is open at both the ends. It is inserted into a flowing stream of oil, S = 0.90, so that one opening is directed upstream and the other is directed upward. Oil inside the tube is 50 mm higher than the surface of flowing oil. The velocity measured by the tube  is , nearly,                                              

(a) 0.89 m/s                 (b) 0.99 m/s

(c) 1.40 m/s                 (d) 1.90 m/s