The Challenge for Economists in the Early Postwar Period Was

The challenge for economists in the early postwar period was to develop a consumption hypothesis that could explain how

A) the saving ratio could remain fairly constant across income groups while the aggregate saving ratio increased over time as average real income grew.
B) the saving ratio for high-income families could be lower than for low-income families while the aggregate saving ratio remained fairly constant over time as average real income grew.
C) the saving ratio for high-income families could be higher than for low-income families while the aggregate saving ratio remained fairly constant over time as average real income grew.