You will be given a definition of a task first, then some input of the task.
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').

Most orthoptists work eight hours a day, ____ or five days a week.\Question: Choose the right answer from options given a) six b) four c) one d) three
Output:
b