Seven-year-old Vinny was a poor sleeper. He had a bad habit of getting up a few times every night, and waking his parents every time, which left the whole family sleep deprived. Vinny’s parents decided to award Vinny with a sticker every time he slept through the night. After five stickers, Vinny will be rewarded with a new DVD of his choice. Vinny’s parents are employing the _______ schedule of reinforcement to help modify Vinny’s sleeping behavior.
a.)variable ratio
b.) fixed ratio