What is the value of air speed if p 1.16 kg/m3?

Question

A pitot--static tube (C = 1) is used to measure air flow. With water in the differential manometer and a gauge deterrence of 75 mm, what is the value of air speed if p 1.16 kg/m3?   

a. 1.21 m/s                   b. 16.2 m/s

c. 5.6 m/s                     d. 71.2 m/s