The transitive relationship refers to any element A. B, and C. If element A and element B have some relationship and element B and element C have this relationship, then element A and element C also have this relationship. Anti-transitive relationship It means that if element A has some relationship with element B and element B has that relationship with element C, but element A has no relationship with element C. According to the above definition, which of the following is relationships that are transitive? ['Greater than relations in natural numbers.', 'Classmate relations in life.', 'Father-son relationship in the family.', 'Natural enemy relationship in the food chain.']