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').

Natural tellurium consists of ____ isotopes.\Question: Choose the right answer from options given a) six b) seven c) eight d) one
c

Serial transfer is the sequential transmission of the ____ bit-voltages that constitute a byte.\Question: Choose the right answer from options given a) ten b) eight c) two d) four
b

Miniature horses tend to be around ____ hands or less.\Question: Choose the right answer from options given a) nine b) eight c) four d) two

a