Which client applications could benefit from the use of a callback object?

A.
A Java applet designed to continuously display the most recent prices of up to five commodities
as they are traded on a commodities exchange

B.
A Java application that retrieves product prices from a Grocery Store database as items are
scanned at the checkout counter

C.
A Java Micro Edition application that allows a mobile phone to receive instant messages over
the Internet

D.
A bank ATM application that retrieves an account balance using a customers ATM card number
and PIN