Answer:
I believe, by process of elimination, it is "Kara's fee for the second child is $5"
Explanation:
It can't be the second option because if her hourly rate for 2 kids was 14, then on hour 2 the total would be $28.
It can't be the third option because Jill's pattern is $11 dollars an hour, and Kara's is adding $9. So, by hour 4, Jill would make $44 and Kara would make $41.
Lastly, it can't be the 4th option because 11-9=2. 2 does not equal 3.