$[4$ marks$]$ An update button on a webpage is used to check for new data from a database.

When the button is clicked the text beside the button is updated to show the time and date

of the last record inserted in to the database. This activity is done asynchronously using

AJAX.

What is the order of execution of the following items in an AJAX asynthronous process call

to a server? $($you only need to provide the letters in your answer$)$

a$.$ Event listener is registered

b$.$ Query issued to database server to retrieve the 'last record added' data

c$.$ Execution of event handler function