Which of the Following Statements Best Summarizes the History of Development

Which of the following statements best summarizes the history of development psychology?

A) In the late 1800s and early 1900s,psychologists began studying children.At the same time,they also began focusing on adult development and aging.
B) In the late 1800s and early 1900s,psychologists began studying children.A decade or two later,they began focusing on adult development and aging.
C) In the late 1800s and early 1900s,psychologists began studying children.In the 1960s and 1970s,they began focusing on adult development and aging.
D) In the late 1930s and 1940s,psychologists began studying children.In the 1960s and 1970s,they began focusing on adult development and aging.