What is the correct answer?

what is the correct answer?

F

F will fill up first.
Water fills A, until it goes across to B, which fills until it goes across to C, which fills until it goes towards D, but is blocked. So C fills until it goes towards J, which fills halfway towards I, where it instead fills L, which empties towards but never reaches H because it is blocked and fills F, which then overflows before L can fill because none of these tanks are enclosed.

Depends how fast the water flows from the tap

Is the pipe from C to D blocked? I won't bother until this is clarified.

the pipe to H appears to be blocked as well, shit diagram desu ne

G

Under some conditions, G is the only one that will eventually be full.

L with pretty much the same reasoning as

G