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').

Rheumatic fever begins one to ____ weeks after an untreated streptococcal infection.\Question: Choose the right answer from options given a) six b) ten c) two d) zero
a

Most children improve in three to ____ days.\Question: Choose the right answer from options given a) seven b) six c) four d) ten
a

Stevia is an economical natural sweetener with virtually ____ calories or aftertaste.\Question: Choose the right answer from options given a) nine b) no c) zero d) six

b