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: Heme is made of ____ pyrrole groups united to form a porphyrin ring.\Question: Choose the right answer from options given a) five b) four c) eight d) six

SOLUTION: b

PROBLEM: Ostriches have ____ stomachs.\Question: Choose the right answer from options given a) four b) nine c) eight d) three

SOLUTION: d

PROBLEM: Platelets are unique in that they have a short life span of just ____ days.\Question: Choose the right answer from options given a) eight b) five c) no d) two

SOLUTION:
b