"If you had not cooked, you would not have been eaten"
The correct answer is: Usingalipika usingaliliwa or Msingalipika msingaliliwa ... the "correct answer" given means "If you had not cooked, you would not have eaten."
If we see cook as having an ergative-type sense, like “The chicken cooked nicely!”, the sentence could even be
Msingalipikwa msingaliliwa. or
Usingalipikwa usingaliliwa.. This would also make more sense. O chicken, if you had not cooked, you would not have been eaten! Kuku, usingalipikwa usingaliliwa! A stative verb would work better, but I don't know if there is for kupika. *usingalipikika?