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').

Bacteria come in ____ basic shapes.\Question: Choose the right answer from options given a) five b) one c) three d) nine
c

Embryos develop and hatch in about four weeks, then spend four to ____ months in the tadpole stage.\Question: Choose the right answer from options given a) five b) nine c) eight d) two
a

Cattle require ____ pounds of feed in order to gain one pound of live weight.\Question: Choose the right answer from options given a) seven b) nine c) three d) two

a