Many Years Ago, Telephone Numbers Had Only Four or Five

Multiple Choice

Many years ago, telephone numbers had only four or five digits. Even now, no more than seven digits (not counting area code) are used for phone numbers. The most reasonable psychological explanation for this is that there is a(n) ________.

A) direct relationship between the number of items in short-term memory and their retention
B) inverse relationship between the number of items in short-term memory and their retention
C) direct relationship between the number of items in the sensory registers and their retention
D) inverse relationship between the number of items in the sensory registers and their retention