Which of the following is correct?

Question

A U-tube manometer with a small quantity of mercury is used to measure the static pressure difference between two locations A and B in a conical section through which an incompressible fluid flows. At a particular flow rate, the mercury column appears as shown in the figure. The density of mercury is 13600 kg/m³ and g = 9.81 m/s². Which of the following is correct?         

      (a) Flow direction is A to B & P_A – P_B = 20 kPa

      (b) Flow direction is B to A & P_A – P_B = 1.4 kPa

      (c) Flow direction is A to B & P_B – P_A = 20 kPa

      (d) Flow direction is B to a & P_B- P_A = 1.4 kPa