Zhang doesn’t want to eat broccoli but his parents keep trying to get him to eat them. At dinner time, if there are any pieces of broccoli on his plate he will scream and shout until they are taken off his plate. His parents always give in to the tantrums and take away the broccoli because his tantrums are becoming increasingly severe and last longer. This is an example of the psychological concept of? Group of answer choices:

-Positive reinforcement
-Negative reinforcement
-Lachanophobia (fear of vegetables)
-Altricial; prolonged