C is the correct answer because in a title, you always want to capitalize the bigger and more describing words.
Hope this helped!
Answer:
0.0000805
Step-by-step explanation:

= 0.0000805
I'd say it's "convergent and doesn't have a sum"
because it's multiplying by 3 to get every new number and switching between ± after every new number. there is no sum because it's an infinite series.