Which was the first version of the Standord-Binet scale to group items according to age level?

In 1908, Hermann Ebbinghaus wrote that "Psychology has a long past, but only a short history." Which statement best captures the idea that Ebbinghaus was expressing?

a. Psychologists, like philosophers, have difficulty learning from their mistakes. b. Questions about human nature have existed for a long time, but only recently have the methods necessary to answer them been developed. c. The field of psychology has existed for a long time, but only recently have scholars recorded the accomplishments of the profession. d. Although psychologists have been doing laboratory research for hundreds of years, little of substance has been discovered about human nature.

A complete cycle through all sleep stages takes approximately:

a. 30 minutes b. 60 minutes c. 90 minutes d. 120 minutes