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').

Q: Waves can sometimes reach ____ feet tall, while still being playful and fun.\Question: Choose the right answer from options given a) nine b) eight c) ten d) no

A: c
****
Q: Natural tellurium consists of ____ isotopes.\Question: Choose the right answer from options given a) six b) seven c) eight d) one

A: c
****
Q: Plants generally are fully dormant with ____ obvious signs of active growth.\Question: Choose the right answer from options given a) four b) two c) five d) no

A:
d
****