The answer is A. All the right numbers are 22, 25, 35, 49.5, and 58. There you go.

notice, the first term is 9.5
from there it goes to 11.5, well, how much is it being added to get 11.5?
well 9.5 + 2, is 11.5, so it was added 2 to 9.5
then it goes from 11.5 to 13.5, namely, 11.5+2 = 13.5
and then 13.5+2 = 15.5 and so on
so, the "common difference" or the common addition value, is 2
how do you find the nth term?
well
It would round up to 31 because the decimal place is greater than 5