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').

Example Input: Human malaria is caused by ____ species of Plasmodium . .\Question: Choose the right answer from options given a) six b) ten c) seven d) four
Example Output: d

Example Input: Alleles segregate independently yielding ____ possible allelic combinations in gametes.\Question: Choose the right answer from options given a) ten b) one c) four d) nine
Example Output: c

Example Input: Fasciculations are present in the tongue at rest, and all ____ proximal extremities.\Question: Choose the right answer from options given a) two b) seven c) no d) four
Example Output:
d