an inflation question

Hi all

I dont know how to add hyperlinks to a newsgroup but I've got a
question that I need to find that answer to at the following URL:

http://www.essaywebs.com/graph.php

The question is written on the page but I will reprint it here for
convenience:

"If the inflation index for Earnings at the 1st Quarter (before
rebasing) was 120, what would the equivalent of the 2nd quarter figure
be?
120
121.2
121.4
121.5
None of these
"

It's a test on a verbal reasoning test and I was wondering if anyone
knew how to work it out? and what is meant in this instance by "before
rebasing"?

Kind regards

Marc

.