Many Years Ago,telephone Numbers Had Only Four or Five Digits

Multiple Choice

Many years ago,telephone numbers had only four or five digits.Even now,no more than seven digits are used for phone numbers.The most reasonable psychological explanation for this is that ________________.

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