What Was the Key Societal Change Post-World War II That

What was the key societal change post-World War II that led to the dissolution of the strong extended family?

A) dual wage-earner families
B) the emergence of therapies that encouraged independence and self-sufficiency
C) the need for families to assume the primary responsibility of educating youth
D) the death of many military men and women left families broken
E) improved transportation increased the mobility of employment