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: Many soils have ____ major layers or horizons, top soil, subsoil and parent material.\Question: Choose the right answer from options given a) one b) two c) seven d) three

SOLUTION: d

PROBLEM: Orangutans spend up to ____ hours a day eating or foraging for food.\Question: Choose the right answer from options given a) seven b) nine c) three d) six

SOLUTION: d

PROBLEM: Ascidian tunicates come in ____ main forms.\Question: Choose the right answer from options given a) three b) zero c) four d) eight

SOLUTION:
a