Depends on how long. $8 every additional hour would be the better deal unless you go at or over 6 hours. If you're planning on babysitting for 5 hours or less, go with option A. If 6 hours or more, go with option B.
If you're babysitting for like 3 1/2 hours the first option if you're babysitting for longer than the second option and also if the kid is bugging you a lot :/ then the second one because you're working harder and the harder you work the more money you should earn :D
