Respuesta :
B. K2O + H2O -> 2KOH
Explanation
for the first one:
left side right side
kk k
oo o
hh h
for the second one:
left side right side
kk kk
oo oo
hh hh
for the third one:
left side right side
kk kk
ooo oo
hhhh hh
for the fourth one:
left side right side
kkkk kk
oooo oo
hhhh hh