Answer:
Pester power
Step-by-step explanation:
Pester power can be defined as the ability of children to pressurize, beg and bargain with their parents into
doing what they want or giving in to their request.
Alexander as a child has seen the advertisement of the candy-like cereal on television, so when he followed his mum to the grocery store, he wanted his mum to purchase the candy-like cereal for him and when she said no, he decided to use the pester power on her by nagging, begging, pouting and bargaining until his mum conceded to his request.