A Student Has Taken a Summer Job Answering Telephone Sales

Multiple Choice

A student has taken a summer job answering telephone sales orders. He quickly learns that it is much easier to remember a customer's 6-digit postal code and 7-digit phone number, but much more difficult to keep track of their 16-digit credit card numbers. According to the research of George Miller, he is having trouble with longer strings of numbers because:

A) the information is staying in his sensory memory.
B) the capacity of sensory memory is quite limited.
C) memory span is only two to four items.
D) memory span is only about five to nine items.