Which of the following series is conditionally convergent?

Psychologists often talk of the magical number "7" - so it is generally assumed that we can keep 7 (more or less, so 5-9 is the correct answer) items in our short term memory - we know this as a result of many experiments.

we can increase this by chunking, so for example "7 8 9 5 3" is harder to remember than "78 95 3" - try it yourself!

the answer is a)

After spending all that time on the research then by all means modify the hypothesis or aim by reporting such. for example the findings did not bring forth what was expected but brought about different yet interesting findings worth exploring so the hypothesis is changed to reflect this new findings.

i may be way off but.