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').

Batteries consist of ____ electrodes immersed in an electrolyte.\Question: Choose the right answer from options given a) two b) eight c) three d) seven
a

Spores have ____ combinations of sexes.\Question: Choose the right answer from options given a) four b) five c) seven d) three
a

Cubs start to walk at ____ months of age.\Question: Choose the right answer from options given a) eight b) nine c) four d) five

c