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: Potassium helps maintain fluid regulation and normal pH. All ____ help normalize.\Question: Choose the right answer from options given a) three b) six c) two d) one

SOLUTION: a

PROBLEM: Ants have ____ stomachs.\Question: Choose the right answer from options given a) two b) nine c) four d) seven

SOLUTION: a

PROBLEM: Natural chromium contains ____ isotopes.\Question: Choose the right answer from options given a) nine b) four c) three d) zero

SOLUTION:
b