For the manometer set up shown in the figure, the pressure difference PA – PB is given by_________________?

For the manometer set up shown in the figure, the pressure difference PA – PB is given by_________________?

A. (ρH – ρair)gH (Correct)
B. (ρH – ρL)gH
C. (ρH – ρL) gH + (ρL – ρair) . g(L – H)
D. (ρH – ρL) gL + (ρL – ρair)gH