homework and exercises - Pressure at the bottom of the fluid (fluid mechanics)

There is a question given my book which is stated below

The three vessels shown in figure have the the same base area. Equal volumes of a liquid are poured in the three vessels the force on the base will be

$1.$ Maximum in vessel $a$

$2.$ Maximum in vessel $b$

$3.$ Maximum in vessel $c$

$4.$ Equal in all the vessels

Given answer: $c$

As the question mentions equal volume of fluid and base area of vessels are same so the fluid must rise to same height in all three and hence pressure at the bottom should be same for all ($p = h\rho g$) and so $d$ should be right option. Please explain why $c$ is the right option and correct me where I am wrong.

Thanks in advance for help !!!

Answer

If you pour a liquid into vessel A, the surface of liquid is rising very slowly, so you need much liquid to rise it about e. g. $5$ cm.

For vessel B you don't need so much liquid for the same height, and for vessel C you need minimum.

So pouring the same volume of liquid into each of these vessels you reach the highest column of liquid — and, consequently, the highest pressure to the base — in vessel C.

As the bases have the same area, the force (= pressure $\times$ area) will be highest in vessel C, too.