Alderfer’s theory categorizes needs into three categories. The most important is? A) Growth needs B) Relatedness need C) Existence need D) None of these Related MCQs: The related facts or observations which are grouped into classes or categories are known as? Which need is on top of Maslow’s hierarchy of needs? ERG theory was given by: In Piaget’s theory, the first two years of life are called the …… stage?