"The Principle of Tender Years" in the Early 20th Century

"The principle of tender years" in the early 20th century refers to

A) the bond between mothers and young children that prompted courts to assume that mothers were the preferred custodial parent.
B) the first five years of a marriage in which courts were reluctant to grant a divorce.
C) the idea that children should not start school until six years of age,later lowered to five years for kindergarten.
D) courts virtual refusal to grant divorces to parents of young children except for extenuating circumstances.