What Belief About Marriage Became Increasingly Common Among Middle- and Upper-Class

What belief about marriage became increasingly common among middle- and upper-class Europeans by the beginning of the twentieth century?

A) That socially acceptable marriages might involve same-sex partners
B) That marriage was fundamentally about the equitable redistribution of property between generations
C) That children should select their own marriage partners
D) That marriage was an outmoded institution that was irrelevant to modern social conditions