Given a sentence with a missing word, pick the answer option that best fills out the missing word in the sentence. Indicate each answer with its index ('a', 'b', 'c', 'd').

Hydra has ____ distinct methods of reproduction, asexual and sexual.\Question: Choose the right answer from options given a) two b) zero c) no d) ten
a

Poles CAN occur at ____ frequency.\Question: Choose the right answer from options given a) six b) four c) zero d) eight
c

Dual nationality is the simultaneous possession of ____ citizenships.\Question: Choose the right answer from options given a) two b) eight c) six d) nine

a