Rails 3：如何为一个父亲，一位母亲和最多两名监护人的孩子建立协会？

Question

如何设定协会入学儿童与父亲，母亲，和两个监护人？

我知道有很多方法来设置它，但你会怎么做呢？我不太清楚如何设置监护人。我目前正在考虑两种选择，也许你可以推荐第三种选择。

选项1个

Enrollments 
belongs_to child 
belongs_to father 
belongs_to mother 

Children 
has_one enrollment 
has_one father 
has_one mother 

Father 
has_many enrollments 
has_many children 

Mother 
has_many enrollments 
has_many children 

选项2

Enrollments 
has_and_belongs_to_many adults 

Adults 
has_and_belongs_to_many enrollments 
has_many children 
# would have a "relationship: father, mother, guardian" 

Children 
has_one enrollment 
has_one father 
has_one mother