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: Gases are perhaps the best understood of the ____ states of matter.\Question: Choose the right answer from options given a) three b) five c) nine d) zero

SOLUTION: a

PROBLEM: Most spiders have ____ eyes and eight legs.\Question: Choose the right answer from options given a) eight b) five c) no d) three

SOLUTION: a

PROBLEM: Today there are essentially ____ distinct types of knowledge.\Question: Choose the right answer from options given a) five b) two c) ten d) three

SOLUTION:
d