TASK DEFINITION: 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').
PROBLEM: Brachiopods are superficially similar to bivalves, both having ____ shells.\Question: Choose the right answer from options given a) two b) eight c) seven d) one

SOLUTION: a

PROBLEM: Bytes are sets of ____ bits.\Question: Choose the right answer from options given a) four b) eight c) five d) ten

SOLUTION: b

PROBLEM: Carbon is unique for ____ main reasons.\Question: Choose the right answer from options given a) three b) two c) eight d) seven

SOLUTION:
b